Sunwise app icon

SunwisePersonalized UV Forecast & Burn Time App for iPhone & iPad

Sunwise is a UV forecast and sun tracker app for iPhone, iPad, and Apple Watch — delivering hourly UV index forecasts and a 7-day UV outlook with personalised burn times based on your skin tone, so you always know when it's safe to be in the sun.

Download on the App Store

Free · iOS 26 or later required

UV tracking built for your skin

Sunwise gives you a complete UV index forecast and sun tracker for iPhone — personalised to your skin tone and accessible on Apple Watch and as a home screen widget.

UV Index Forecast

Get hourly and 7-day UV forecasts personalised to your exact location. Know when levels are rising, when to seek shade, and plan outdoor activities around the safest windows of the day.

Burn Time

Sunwise calculates your personalised burn time based on your skin type and the current UV index. Know exactly how long you can safely spend in the sun before protection is needed.

Apple Watch

A native watchOS companion that keeps UV data right on your wrist. Glanceable complications show your current UV index and remaining burn time, so you're never caught off guard.

Widgets & Intents

Home Screen and Lock Screen widgets keep your UV index front and centre without opening the app. App Intents bring Sunwise into Shortcuts and Siri for hands-free access anywhere.

How Sunwise works

Three steps to a UV forecast tailored to your skin tone — on iPhone, iPad, and Apple Watch.

  1. 1

    Set your skin type

    Tell Sunwise your Fitzpatrick skin type — from Type I (very fair, always burns) to Type VI (very dark, rarely burns). This takes seconds and only needs to be done once.

  2. 2

    Get your personalized UV forecast

    Sunwise uses your GPS location to deliver hourly and 7-day UV index forecasts. Unlike generic weather apps, every reading is paired with a burn time calculated for your skin — so you know exactly how long you can stay outside safely.

  3. 3

    Check your UV exposure at a glance

    View your UV index and burn time from your iPhone Home Screen widget, Lock Screen, or Apple Watch complication — no need to open the app. Siri and Shortcuts integration let you check hands-free.

Frequently asked questions

Everything you need to know about Sunwise and UV forecasting.

What is a UV index forecast app?
A UV index forecast app shows you the predicted UV radiation levels for your location throughout the day. Sunwise goes further by personalising the forecast to your specific skin tone, calculating exactly how long you can safely spend in the sun before needing sun protection. Not sure what the UV numbers mean? Read our UV index guide.
How does Sunwise personalise UV forecasts for my skin?
Sunwise uses your Fitzpatrick skin type — a standard scale from Type I (very fair) to Type VI (very dark) — combined with the real-time UV index at your location to calculate a personalised burn time. This gives you a precise safe-exposure window rather than a generic UV number. Not sure which type you are? Take the Fitzpatrick skin type quiz.
How do I find my Fitzpatrick skin type?
Use a self-assessment based on the standard skin phototype questionnaire — covering eye color, hair color, freckling, how you burn and tan, and recent sun exposure. Our Fitzpatrick skin type quiz walks through all nine questions with the scoring rubric so you can find your type (I–VI) in a few minutes, then shows the burn time you can expect at different UV levels.
Does Sunwise work on Apple Watch and as an iPhone widget?
Yes. Sunwise includes a native watchOS companion app with glanceable UV index and burn time complications, plus Home Screen, Lock Screen, and StandBy widgets for iPhone and iPad so your UV forecast is always front and centre. See our guide on the UV index on Apple Watch for complication setup, or the iPhone UV index widget guide for Home Screen, Lock Screen, and StandBy steps.
How do I add a UV index widget to my iPhone?
Install a UV forecast app that ships widgets — Sunwise provides them for Home Screen, Lock Screen, and StandBy. Long-press the Home Screen, tap the plus button, search for the UV app, pick a size, and tap Add Widget. For the Lock Screen, long-press the Lock Screen, tap Customize, and pick an inline, circular, or rectangular widget. The UV index widget for iPhone guide walks through each surface with screenshots and widget-size guidance.
Can I see the UV index on my Apple Watch with Sunwise?
Yes. Sunwise ships with a native watchOS app and UV index complications for most Apple Watch face families — including Modular, Infograph, and Meridian — plus a UV widget for the Smart Stack. Complications pair the real-time UV index with your personalized burn time so you can see both at a glance. Read our Apple Watch UV index guide for setup steps.
How accurate is the UV index forecast in Sunwise?
Sunwise uses Apple WeatherKit — the same data source as Apple's own Weather app — to deliver hourly and 7-day UV index forecasts based on your precise GPS location. UV levels are modelled from solar position, cloud cover, altitude, and ozone data, giving you a reliable forecast to plan outdoor activities safely. For a deeper look at how UV data is sourced and why apps can sometimes disagree, read our UV index accuracy guide.
Why do different UV index apps show different numbers?
Each UV app pulls from a different upstream data source — Apple WeatherKit, NOAA, OpenUV, OpenWeatherMap — and each models UV slightly differently. Differences of ±1 between reputable sources are normal and don't mean one is wrong. Sunwise uses Apple WeatherKit so the raw UV number matches what you see in Apple Weather. Our UV index accuracy guide explains the major data sources and why they vary.
Is Sunwise available as a UV index app on iOS and iPadOS?
Yes — Sunwise is a native UV index app for iOS and iPadOS, built for iPhone and iPad. It uses your device's GPS location to deliver real-time and hourly UV index forecasts with personalised burn time recommendations tailored to your Fitzpatrick skin type.
How does Sunwise work as a sun UV tracker on iPhone?
Sunwise acts as a sun UV tracker for iPhone by combining real-time UV index data from your GPS location with your personal skin type profile. It shows the current UV level, forecasts peak UV hours ahead, and calculates how long you can safely spend outdoors — viewable at a glance from your Home Screen widget or Lock Screen. See our step-by-step guide on how to check the UV index on iPhone.
Can I use Sunwise to plan a tan?
Yes. Sunwise shows the hourly UV index for your location plus your personalized burn time, which is the most useful pair of numbers for planning a tanning session — find a UV 3–5 window, watch your burn time, and head inside before it drops too low. See our UV index for tanning guide for a skin-type-by-skin-type breakdown.
Is Sunwise the same app as EPA's SunWise?
No — Sunwise and EPA's SunWise UV Index are two different apps. EPA's SunWise is a U.S. Environmental Protection Agency reference app for ZIP-code UV forecasts and general sun-safety education. Sunwise (this app) is an independent personalized UV forecast app for iPhone and iPad that calculates a burn time tailored to your Fitzpatrick skin type, with native Apple Watch complications and Home Screen widgets.
Which is the best UV index app for iPhone?
It depends on what you want from it. Apple's built-in Weather app is the easiest way to glance at the current UV index, but it shows the same number to everyone. Sunwise is built for users who want a personalized burn time based on their skin type, plus Apple Watch support and Home Screen widgets. See our full comparison of the best UV index apps for iPhone for a side-by-side look at the top options.
How does Sunwise help prevent sunburn?
Sunwise turns the UV index forecast into a personal burn time in minutes based on your Fitzpatrick skin type — so you know exactly when sunburn risk starts at the UV level outside. Hourly and 7-day forecasts let you plan around peak UV, Apple Watch complications and Lock Screen widgets keep your remaining safe minutes always visible, and a six-step prevention routine pairs the burn time with shade, SPF, and clothing. See our guide on how to prevent sunburn for the full skin-type-aware checklist.
How long does it take to get sunburn?
It depends on the UV index and your Fitzpatrick skin type — burn time is roughly inversely proportional to UV. Very fair (Type I) skin can start to burn in about 10 minutes at UV 10 and 20 minutes at UV 5; darker (Type V) skin can take 45–90 minutes at the same UV levels. Sunwise calculates the exact number in real time for the current UV at your location. The sunburn prevention guide has a full table of typical burn times by Fitzpatrick type.