⚡ Free · No signup · Works offline

Know when NOT to wash your car.

RainOrRinse defaults to "you don't need to wash" — and only speaks up when there's a real signal. No more washing right before a downpour. No more nagging when your car is fine.

Try it free → How it works
Built in Singapore Works worldwide Your data stays on your device
RainOrRinse 📍 Singapore
Today
✅ You're good — skip it
Car's clean. 4 days until your usual wash — no rush. Go enjoy your day.
✨ Clean 🛡️ Ceramic 4d to cycle
Wash cycleEvery 7 days
Last wash3 days ago · 🌤️ dry
Next rainLight · Wed PM
Grime score 4 · clean
No rain hit you. No contaminants logged. The app stays quiet until day 6.

If any of these sound familiar…

Most car owners are stuck guessing. Detailing forums have rules of thumb but no tool actually runs the numbers for you.

😤 You spent 2 hours hand-washing and watched a thunderstorm hit 5 minutes later.
🤔 You skipped a wash because "it'll probably rain" — and it didn't rain for a week.
🐦 You spotted bird droppings, told yourself you'd clean them tomorrow, and found them etched into the paint by Friday.
🌫️ You hand-washed during haze season not knowing the acidic particles were settling on your bonnet hours later.
🛡️ You have PPF + ceramic and your detailer said "you can go 60 days" — but no one told you bird droppings stain the film faster than paint.
How it works

Three signals. One answer.

No accounts. No setup beyond 30 seconds of "what's your car like?"

1
📍

Read your local conditions

Pulls hourly weather, 16-day forecast, UV index, and PM2.5 air quality from your location.

2
🚗

Combine with your car

Paint colour, protection (wax / ceramic / PPF), parking exposure, tree canopy, coastal salt-air — all factored in.

3
✨

Tell you what to do

Wash now, wait for Wednesday's window, or just rinse off the residue. Plus a grime score so you can audit the call yourself.

The only car-wash app that knows when haze is settling on your bonnet.

We model UV index, PM2.5 (especially during SE Asian transboundary haze), bird-droppings chemistry, and tropical coating life. Most weather apps tell you if it'll rain. We tell you if you should wash.

Smart features

Real intelligence, not just a rain checker.

📅

Best wash window picker

Scans the next 14 days for the longest dry stretch with the best time of day. Add to calendar or share with one tap.

🚨

Bird droppings 6-hour clock

Uric acid (pH 3-4) etches clear coat within hours — faster on hot paint. We start a countdown the moment you log it.

🌫️

Haze + air-quality aware

Bumps grime urgency during haze events. PM2.5 over 35 µg/m³? The car needs a wash sooner than the rain forecast suggests.

🛡️

Coating-aware schedule

Bare paint, wax, sealant, ceramic, graphene, PPF, PPF+ceramic — each gets the right max-days and grime tolerance. Tropical climate? We adjust for that too.

📊

Live grime score

A visible meter showing how much dirt + acid + brake dust has built up. Green to red, with the math broken down so you can audit the recommendation.

🌳

Environment toggles

Park near trees? Live by the coast? Flip a switch and the engine factors in higher contamination + salt-air corrosion.

Built for everyone who actually cares about their car.

🚙
Daily drivers
Tired of timing rain wrong
✨
Show-car owners
Need precision timing
🛡️
PPF + ceramic crowd
Protect the protection
🏝️
Tropical climate
SG, MY, ID, TH, PH and beyond
Why we built this

Singapore weather is a chaos engine.

We're car enthusiasts here in SG. We got tired of timing rain wrong. The detailing community has decades of rules of thumb — "wash every 2 weeks", "wait 48 hours after rain", "PPF needs more care than people think" — but no app actually crunched the local forecast against the chemistry of how a car gets dirty.

So we built one. RainOrRinse is what we wished existed three years ago.

No accounts. No emails. No tracking pixels. Your data lives on your device. Always free for the core app.

Common questions

Is it really free?
Yes. The core app is always free with no ads, no signup, no email capture. Future "Pro" features (multi-car, longer forecast detail, history export) may be paid, but everything that's there now stays free.
Does it work outside Singapore?
Yes — anywhere with weather data, which is almost everywhere. The engine adjusts for tropical vs temperate climate automatically. Haze data may be missing in some countries; weather still works.
Do I need an account?
No account, no signup, no email. Everything is stored locally on your device. Install it like any web app — Add to Home Screen on iPhone, Install from menu on Android.
Will it work offline?
Yes. The app caches itself the first time you load it. The latest weather is also cached, so even if you have no signal, you'll see the last reading and your wash schedule.
What about my data?
All your data — car details, wash history, log events — lives in your browser's local storage on YOUR device. We don't have a server that knows who you are. You can export everything as JSON from Settings whenever you want.
How accurate is the forecast?
We use Open-Meteo (free, open-source weather aggregator) which combines ECMWF, GFS, ICON, and other major weather models. Accuracy is high for the next 2-3 days, decent for 5-7, and increasingly approximate beyond that. The 14-day picker uses confidence-weighted scoring.
I have PPF. My detailer said 60 days between washes. Why does this app say less?
Industry sources (XPEL, 3M, SunTek) all publish wash schedules of 1-2 weeks for PPF, because the film itself stains from bird droppings and sap faster than clear coat. The "60 days" claim is marketing, not chemistry. Our defaults follow what the film manufacturers actually recommend.
Can I add multiple cars?
Not yet — but it's on the roadmap. Right now you can add one car. Multi-car support is the most-requested feature and is coming next.

Stop guessing. Wash on the right day.

Takes 30 seconds to set up. Free forever.

Try me now →

Or add it to your home screen for one-tap access — works just like a native app.