Tomorrow's UV index: see the forecast, the peak and the plan

Check tomorrow's UV for your city

Every city page shows tomorrow twice: the hourly curve (tap through to tomorrow's hours) and the 7-day outlook with each day's peak. Popular cities: New York · Los Angeles · Chicago · Miami · Houston · Phoenix · Seattle · London · Madrid · Sydney · Tenerife · Cancún — or search any of 420+ cities from the homepage.

How tomorrow's UV rays are forecast

Tomorrow's clear-sky UV is close to certain: it follows the sun's angle (fixed by the calendar), the ozone layer (measured daily by satellite) and your altitude. Forecast models like Open-Meteo — the source behind our data, refreshed every 15 minutes — combine those with expected cloud cover to produce an hourly UV radiation forecast for tomorrow that's typically accurate within about one index point.

Why tomorrow can differ from today

Three things move the number day to day: cloud cover (the big one — though even overcast skies pass 20–80% of UV rays), ozone fluctuations (a thin-ozone day adds a point), and in summer the slow seasonal climb toward the solstice. A UV 6 today can genuinely be a UV 8 tomorrow — which is exactly why checking ahead beats assuming.

Get tomorrow's peak as a morning notification

The easiest version of planning ahead: our free UV spike alert sends a push notification in the morning when tomorrow's — that day's — UV will reach high levels at your location. Enable it with one tap on any city page. No app, no account, and it only speaks up when protection actually matters.

Planning a high-UV day tomorrow?

Three moves cover most of the risk: schedule outdoor time before 11:00 or after 16:00 (see the best-time guide), know your personal burn window with the burn-time table for tomorrow's peak value, and pack accordingly — our packing checklist covers the full kit. Tanning tomorrow? Read which UV index actually works for tanning first.

Frequently asked questions

How accurate is tomorrow's UV forecast?

One-day UV forecasts are highly reliable: tomorrow's clear-sky UV depends on the sun's angle and ozone, which are precisely predictable. The main uncertainty is cloud cover — and even heavy cloud still lets 20–80% of UV rays through.

When will UV rays peak tomorrow?

UV peaks around solar noon — typically between 12:00 and 14:00 local time. Every city page shows tomorrow's exact peak hour in the hourly curve and the 7-day outlook.

Will UV rays be strong tomorrow if it's cloudy?

Usually yes. Light cloud barely reduces UV, and up to 80% passes through. If tomorrow's forecast shows UV 3 or higher, plan protection regardless of the cloud icon.

Can I get tomorrow's UV index as a notification?

Yes — uvindex.now sends a free morning push alert when tomorrow's UV will be high at your location, so you know before you head out. Enable it on any city page; no app or signup needed.

What's the difference between UV rays and the UV index?

UV rays are the radiation itself; the UV index is the 1–11+ scale that measures how strong those rays are at ground level. “UV 8 tomorrow” means sunburn-strength radiation — fair skin burns in under 20 minutes.