Learn how to paint a rainy day watercolor using the wet-on-wet technique. A working artist explains step by step how to create soft skies, reflections, and atmospheric depth.
By Joy Mukherjee — self-taught watercolor artist, Kolkata. Exhibited at Indian Art Carnival, Shantiniketan 2025.
Quick Answer — How to Paint a Rainy Day Watercolor
- Wet-on-wet is the technique — wet your paper first, then drop pigment in. The paint spreads and softens on its own, creating the hazy, atmospheric quality monsoon skies actually have.
- Water controls everything, not color — the amount of water on your paper and brush determines whether edges are soft or hard, whether paint spreads or sits still. Hue and saturation matter far less than most beginners think.
- Value is the priority — how light or dark a passage is matters more than which color it is. A grey sky in watercolor is correct not because you mixed the right grey, but because you got the value relationship right between the sky and the land beneath it.
- Too much water on paper = blooms and loss of control. Too little = the paint drags and refuses to spread. Finding the right balance — paper shiny-wet but not pooling — is the entire skill.
- Monsoon subjects ideal for wet-on-wet: overcast skies, misty treelines, rain on water, soft distance in landscape, flooded village paths reflecting sky.
- Beginner mistake to avoid: adding more paint to fix a wet wash. Wait for it to dry completely. Every touch on a drying wash makes it worse.
- Atmospheric Case Study: Tea Stall demonstrates how a glowing amber tea stall can be balanced against a heavy monsoon sky using controlled wet-on-wet washes.
How to Paint a Rainy Day Watercolor
Painting rain in watercolor is less about drawing raindrops and more about atmosphere — soft edges, reflections, muted contrast, and diffused light. The wet-on-wet technique used for creating a rainy day watercolor is exactly what creates this effect. This sympathy between the medium and the subject runs deeper than technique — it has been the foundation of Indian monsoon painting for over 500 years, from Ragamala miniatures to contemporary watercolor.
If you are trying to learn how to paint a rainy day watercolor, this technique — wet-on-wet — is the foundation. It is the only way to translate the physical weight of a true monsoon onto paper.
My experience of rain in Kolkata is not humid in the polite, European sense — actually wet. The kind of July where the boundary between the sky and everything beneath it ceases to be meaningful, where the street outside my window is a mirror by eight in the morning, where the trees on the far side of the road dissolve into grey-green suggestion rather than individual leaves. I painted Monsoon Village on a day like that. Not from a photograph. From the view through the window, and from the way the wet air made everything soft at the edges. My latest work, Tea Stall, explores this same boundary — where the rain-soaked road becomes a mirror for the amber light of a roadside stall.
The amber glow of the Tea Stall held against a heavy monsoon sky — a study in light temperature and wet-on-wet atmosphere.
That softness is what wet-on-wet watercolor technique is for.
If you have ever wondered how painters get that hazy, atmospheric quality in rain scenes — the treeline that bleeds into the sky, the path that seems to dissolve into mist, the sky that has no hard edges anywhere — this is the post that explains it. Not in theory. In practical terms, beginning from the beginning, including the part where things go wrong and what to do about it.
Watch How to Paint a Rainy Day Watercolor (Wet-on-Wet Demonstration)
I recorded this tutorial specifically to show what water control looks like in practice, because some things are genuinely easier to understand by watching than by reading. This video shows how to paint a rainy day watercolor using the wet-on-wet technique, focusing on water control, soft edges, and atmospheric blending.
What I am demonstrating there — and what I want you to take from it before anything else — is that value, how light or dark a passage is, matters more than hue or saturation. You can paint a monsoon sky with almost any grey-blue you have on your palette. What makes it read correctly is whether it sits at the right value relative to the land beneath it. And in watercolor, value is controlled almost entirely by how much water you use, not which color you reach for.
That is the whole lesson. Everything else in this post builds on it.
What Wet-on-Wet Actually Means
The phrase sounds technical. It is not.
Wet-on-wet simply means: you put water on the paper first, and then you add paint into that wet surface. The wet paper and the wet paint meet, and the paint spreads into the moisture — softening at the edges, diffusing outward, going where the water already is.
The alternative is wet-on-dry: wet paint applied to completely dry paper. This gives you sharp, controlled edges. The paint stays exactly where you put it.
What makes watercolor unique as a medium is that both techniques exist in the same painting, often within centimetres of each other. The soft sky is wet-on-wet. The hard line of the rooftop against the sky is wet-on-dry. You switch between them by simply waiting for the paper to dry — or deliberately keeping it wet.
Monsoon paintings live mostly in wet-on-wet territory. This is not an accident. (In fact, there is a 500-year history of how Indian artists have approached this subject—you can read my full cultural guide on the monsoon in Indian art). The monsoon sky has no hard edges. The air is full of moisture. The treeline across a flooded paddy field dissolves into grey-green blur. The technique mirrors the subject because the technique is literally about water behaving like water.
The One Thing That Changes Everything: Controlling Water, Not Color
Here is what nobody tells beginners clearly enough.
When a wet-on-wet passage goes wrong — when the paint blooms where you didn't want it to, or drags instead of spreading, or dries with a hard edge in the middle of what should be a soft sky — the instinct is to blame the color. Wrong mix. Wrong brand. Wrong pigment.
Almost always, it is the water.
Specifically, the relationship between how wet the paper is and how wet the paint on your brush is. This relationship has three states:
1. Too much water on paper, too much on brush The paint spreads everywhere. You lose all control. The color diffuses so much it becomes pale and flat. This is why beginners' skies go grey and watery even when they mixed a strong blue.
2. Too little water on paper (or paper already drying) The brush drags. The paint sits where you put it instead of spreading. If you try to add more paint into a wash that is half-dry, you get a bloom — a hard-edged explosion of new pigment pushing the old pigment outward. This is the most common and most heartbreaking mistake in watercolor. I have done it hundreds of times.
3. The right balance — paper shiny-wet, brush loaded but not dripping Paint spreads smoothly. Edges soften where you want them soft. You can drop in a second color and watch them blend without fighting each other. This is the state you are aiming for.
The skill in wet-on-wet watercolor is learning to read the surface. You learn to see — from the way light catches the sheen of the wet paper — whether you are in state one, two, or three. This takes practice. There is no other way to develop it.
Why Monsoon Is the Perfect Subject to Learn This Technique
Most subjects punish wet-on-wet mistakes immediately. A flower painted wet-on-wet that goes wrong looks like a muddy stain. A portrait that bleeds has obvious problems.
Monsoon landscapes are forgiving in a way most subjects are not. Because the subject itself is atmospheric and soft, the accidents that wet-on-wet produces — unexpected blooms, colors that drift where you didn't intend — often become the painting. A bloom in a sky passage reads as a cloud. A color that drifted from the treeline into the sky reads as mist. This is the same logic used in the Nature series, where the mist at the base of The Hidden Fall was created by dropping wet pigment into a pre-wetted surface. Where the Light Waits was made partly this way. The atmospheric quality in the sky didn't arrive from planning. It arrived from setting up the right conditions and then letting the pigment do what it does on wet paper.
This is why I love watercolor — it is the only medium where the material has genuine agency, and monsoon subjects are where that agency works in your favour.
Beginner Step-by-Step: Painting a Rainy Day Sky in Watercolor
You do not need expensive materials for this exercise. A small sheet of watercolor paper (at least 200gsm, cotton if possible), a large and a medium round brush, and three colors: a grey-blue, raw umber or burnt sienna, and any green. That is genuinely enough for your first rainy day watercolor.
Step 1 — Wet the paper
Use a wide, clean brush and cover the sky area with plain water. You want the paper to be visibly wet — if you tilt it, you should see the light shift across the wet surface. If there are dry patches, go back and wet them.
Wait ten seconds. Tilt the paper slightly. If water runs freely, it is too wet. Blot with a dry brush or paper towel. If the sheen is disappearing, work quickly — you have a short window.
This wetting step is the most important step. Everything else depends on getting this right.
Step 2 — Drop in the sky
Mix a loose, relatively dilute grey-blue. For monsoon skies, think: more grey than blue. The sky during peak monsoon is not the bright blue of a clear day — it is a heavy, luminous silver-grey with blue undertones.
Load your brush generously and touch it to the wet paper near the top of the sky area. Watch what happens. The paint should spread outward from where you touched, following the moisture in the paper. Do not push it. Let it go where it wants.
Drop in a second touch of paint further down, a slightly different value — either lighter or darker. They will bleed into each other in the wet surface. This blending is the wet-on-wet technique working correctly.
The critical rule: once you drop in paint, do not add more to the same area until it is completely dry. Every touch on a drying wash makes it worse without exception.
Step 3 — The horizon and treeline
While the sky is still wet, mix a slightly darker, greener grey. This becomes the distant treeline or the horizon.
Touch the brush at the bottom of your wet sky area. The dark green will bleed upward slightly into the wet sky — this upward bleed is what creates the soft, misty quality where trees meet sky in a rainy day watercolor. You are not painting it. You are allowing it.
This is the moment that feels like magic the first time it works. The line between sky and trees becomes uncertain, atmospheric, true to the actual quality of humid air.
Step 4 — Foreground (wet-on-dry)
Let the sky dry completely. This may take twenty minutes. Do not rush it.
Once it is dry, switch to wet-on-dry for any foreground elements — a path, a building edge, the dark trunks of trees in the middle distance. These get hard edges because they are painted onto dry paper. The contrast between the soft, atmospheric background and the harder foreground creates depth without effort.
In Monsoon Village, the rooftops and the vegetation in the immediate foreground were all painted wet-on-dry over a wet-on-wet background. The technique combination is the entire visual logic of the painting. Similarly, the mist-shrouded ridgelines in Morning in Kumaon 1 depend on this contrast between soft background washes and hard foreground anchors.
Step 5 — Reflections
A flooded monsoon path reflects the sky. To paint this, you simply repeat the sky colors — the same grey-blue — in the lower portion of the paper using wet-on-wet again, but with slightly less water and slightly more pigment than the sky. The reflection is always marginally darker and more saturated than the sky above it. Not much. But enough.
The horizontal nature of the reflection strokes, versus the more diffuse quality of the sky, is what makes the eye read it as a convincing watercolor rain effect. In Tea Stall, these reflections carry the warmth of the stall's light, showing how wet-on-wet can hold both atmosphere and specific light temperature.
The Specific Challenges Monsoon Watercolor Creates
Working in Kolkata during the actual monsoon months changes the technique entirely. This is something Western watercolor tutorials never address because they are written from dry studios in temperate climates.
When ambient humidity is above 80%, washes that would dry in five minutes in December take thirty minutes or more. The wet window stays open far longer. This sounds helpful. In practice it means you are waiting for passages to dry when you want to add detail, and the increased drying time increases the risk of unwanted bleeds from adjacent wet areas touching each other.
I adjust for this by working on smaller passages at a time during monsoon months, letting each section fully dry before moving adjacent to it. I also keep a hair dryer nearby — not to force-dry passages, which can cause the paint to lift unpredictably, but to confirm that a passage is genuinely dry before I paint next to it.
The humidity also affects how pigment granulates. In A Snowy Morning in Kedarnath, the granulation in the mountain passages — that gritty, atmospheric quality — behaved completely differently than it does in the dry winter months. The same pigments, the same paper, different results, because the environment was different.
What makes watercolor unique as a medium is precisely this: it is a negotiation with your environment, not just your subject. It is also why watercolor is specifically suited to Indian conditions.
Value, Not Color — The Most Important Lesson
I want to come back to this because it is the thing that changes everything when beginners finally understand it.
Most people approach watercolor color-first. They think about which blue to use for the sky, which green for the trees, whether to use burnt sienna or raw umber for the path. This is understandable — color is visible and nameable. But in watercolor, and particularly in wet-on-wet atmospheric work, color is almost the last thing that matters.
What matters is value. How light is this passage relative to the one next to it?
A monsoon sky works because it is lighter than the treeline below it. Not because it is the correct shade of grey-blue. The treeline reads as dark vegetation not because it is a recognizable green, but because it is several values darker than the sky. The reflected water reads as sky-colored not because it is the same hue, but because it is close to the same value.
When a painting looks wrong and you cannot identify why, check the values before you change any colors. Hold the painting at arm's length and squint. Does the sky look lighter than the ground? Does the distance look lighter than the foreground? If not, value is the problem, and adding more color will not fix it.
This is why the video embedded above emphasizes water control so heavily. Water controls value in watercolor. More water = lighter value. Less water = darker value. The color itself is secondary.
Common Mistakes — And What They Actually Mean
The bloom (cauliflower mark) Wet paint touched to a wash that was partially but not completely dry. The new moisture pushes the old pigment outward in a hard-edged ring. Prevention: wait longer. The only way to know if a wash is dry is to touch the back of the paper (which shows heat from evaporation) or use a lamp held close — dry paper is matte, wet paper has a sheen.
The flat, grey sky Almost always too much water and too little pigment. The pigment diffused so much it lost its value. Mix stronger than you think you need to — watercolor dries 30-40% lighter than it looks wet.
Paint that won't spread Paper dried between wetting and applying paint. Re-wet carefully, but know that if the paper has any paint on it already, re-wetting can lift that paint unpredictably. Prevention: work more quickly after wetting, or work in smaller sections.
Muddy colors where two wet areas met Usually two complementary or near-complementary colors bled into each other on the wet surface. This is particularly common with monsoon greens (yellow-bias green) bleeding into purplish-grey skies. Prevention: keep wet areas from touching until both are dry, or accept the bleed as part of the painting — some of the most beautiful passages in wet-on-wet work are accidents.
If you are learning how to paint rainy day watercolor scenes, studying original paintings helps far more than tutorials alone — you can see how water, pigment, and paper interact in real light.
How These Techniques Work in Real Paintings
Every atmospheric passage in the landscape gallery on this site was built with wet-on-wet as the foundation.
Silent Harbor at North — the entire sky and mountain snowfield were wet-on-wet, pigment dropped into a pre-wetted surface and allowed to granulate as it dried. The mountain edges disappear into the sky because both were wet at the same time.
Morning in Kumaon 1 — the soft atmospheric light in the valley was the result of a very dilute wet-on-wet wash in the distance, with progressively harder and darker wet-on-dry strokes in the foreground creating depth.
Quiet Afternoon in the Hills — the sky-to-land transition is a wet-on-wet passage. The buildings are wet-on-dry. The contrast between soft and hard reads as the difference between air and solid matter.
Remnant — the fading light on the distant shore uses wet-on-wet to create that quality of light that seems to come from behind the paint rather than from the surface of it. This is why original watercolor paintings feel more alive than prints — the luminosity is structural, built into how the paint and paper interact with light.
What to Practice First
If you have not tried wet-on-wet before, do not start with a full painting. Start with this single exercise:
Take a quarter sheet of watercolor paper. Wet the entire surface with clean water. While it is shiny-wet, drop in a dark color at the top and a lighter color at the bottom. Watch what happens. Do not touch it again.
Do this ten times with different pigments. Notice which ones granulate (cluster into texture as they dry) and which ones stay smooth. Notice how the spread changes as the paper gets drier. Notice that the final result is always lighter than it looked wet.
That exercise teaches more about wet-on-wet than any amount of reading. The knowledge is in your hands and eyes, not in the theory.
When you are ready to attempt a monsoon sky specifically, Monsoon Village is the painting I return to when I want to remember what this technique is for. It is not a complex composition. It is almost entirely atmosphere — soft edges, mist, the quality of air that has been rained on. Everything in it came from water control, not color choice.
A Note on Materials
You do not need expensive paper to practice wet-on-wet. But you do need paper that handles water without immediately buckling. 300gsm is the standard — at this weight, the paper can absorb the water you put on it without warping into shapes that cause paint to pool in the wrong places. Read the full guide on which papers handle wet-on-wet best. Lighter paper buckles, and a buckled surface changes where the wet paint goes.
For pigments, the main thing to know is that student-grade paints granulate weakly and lose their value when diluted. This matters more in wet-on-wet than in any other technique because you are working with a great deal of water. If your washes keep going flat and grey, the paint may be the problem. Professional-grade paints — Winsor & Newton Professional, Daniel Smith Extra Fine — carry pigment at a concentration that survives dilution and still arrives at the right value on the paper.
A detailed explanation of which papers and pigments do what, and why the differences matter, is in the what makes watercolor unique as a medium post.
If You Want to Own a Monsoon Painting
All of this — the wet-on-wet technique, the water control, the value relationships — is visible in the originals in a way it simply cannot be in a print. The granulation has physical texture. The soft edges have a quality that changes slightly depending on the angle of light and where you are standing.
If you have been reading about how these paintings are made and want to understand what that means for collecting one, the guide on how to buy original watercolor paintings online covers everything you need to know. And if you are wondering whether to buy from an artist's website directly, the answer to that question is here.
You can browse currently available originals including Monsoon Village and other atmospheric landscape works at the gallery or the buy original paintings page.
About the Artist
Joy Mukherjee is a self-taught watercolor artist based in Kolkata, India. Working primarily in landscape and narrative subjects — Indian Himalayan light, monsoon village scenes, Scandinavian harbour mornings — their paintings have been exhibited at the Indian Art Carnival Season 7, Shantiniketan (December 2025), and are held in private collections across India and abroad. You can follow the process on Instagram or browse the full portfolio at artbyjoy.shop.
Explore the new Nature Watercolor Collection, browse Original Landscape Paintings, or view the Watercolor Mountain Paintings.
Frequently Asked Questions
What is wet-on-wet technique in rainy day watercolor painting?
Wet-on-wet means applying wet paint onto paper that has already been wetted with clean water. The paint spreads and diffuses into the moisture, creating soft edges and atmospheric blending that is impossible to achieve on dry paper. It is the primary technique for painting skies, mist, atmospheric distance, and any subject where soft edges are needed — including the overcast skies, flooded paths, and misty treelines of Indian monsoon scenes.
How do I control the spread of paint in wet-on-wet watercolor?
By controlling the amount of water on the paper and the amount on the brush. The paper should be shiny-wet but not pooling — if water runs freely when you tilt it, it is too wet. Your brush should be loaded but not dripping. The drier the paper relative to the brush, the less the paint will spread. The wetter the paper, the more. This balance is the skill, and it is learned through practice, not instruction.
Why does my watercolor sky look flat and grey instead of luminous?
Usually too much water and too little pigment. When paint is heavily diluted and dropped into a very wet surface, the pigment disperses so much it loses its value and looks washed out. Mix stronger than you think you need to — watercolor dries significantly lighter than it looks when wet. Also check your pigment quality: student-grade paints dilute poorly and tend toward grey at high water ratios.
What colors do I need to paint a monsoon sky?
Very few. A blue-grey — Payne's grey, or ultramarine mixed with burnt sienna, or any grey-blue you have — is the main sky color. Raw umber or burnt sienna for warmer cloud passages. A mid-green or sap green for the distant vegetation. You do not need more than three colors for a basic monsoon sky study. Value relationships between these colors matter far more than which specific colors they are.
Why do my wet-on-wet passages get that cauliflower bloom mark?
Because you added paint to a wash that was partially but not completely dry. When wet paint touches a drying (not dry) wash, the new moisture pushes the old pigment outward in a hard-edged ring. The only prevention is patience — wait until the previous wash is completely dry (matte, no sheen on the surface, back of paper cool to touch) before painting adjacent areas. Once a bloom has happened, it cannot be removed without lifting the paper's surface.
Can I practice wet-on-wet without painting a full scene?
Yes, and this is actually the better approach. Wet a quarter sheet completely, drop in two or three colors, and watch what happens without trying to control the result. Do this ten times with different pigment concentrations and different amounts of water on the paper. This teaches you the material's behavior directly — which is the only real way to develop the judgment for when to touch and when to wait.
Is wet-on-wet watercolor suitable for complete beginners?
Yes, with one condition: manage your expectations for the first attempts. The technique is simple to begin but develops subtlety over time. Monsoon atmospheric skies are particularly forgiving subjects for beginners because the softness of the technique suits the softness of the subject — mistakes often read as atmospheric quality rather than errors. Start with sky studies before attempting full compositions.
How is painting monsoon in watercolor different from painting a clear sky?
A clear sky has a value gradation from deep blue at the top to pale blue at the horizon — this is painted wet-on-wet but with more controlled pigment concentration. A monsoon sky is heavier, more uniform in value, with grey dominating the blue. The challenge is keeping it luminous rather than dead — which comes from using slightly warm tones in the grey mix (burnt sienna or raw umber with the blue) and from ensuring the paper is properly wet so the pigment granulates rather than sitting flat.
How do you create a watercolor rain effect?
Rain is not painted as individual drops. It is suggested through soft edges, diffused light, reflections, and reduced contrast using wet-on-wet technique.
Written by Joy Mukherjee
Joy Mukherjee is a watercolor artist who paints landscapes, village scenes, and atmospheric moments using transparent watercolor on premium 100% cotton watercolor paper. His work is born from memory, light, and atmosphere.
