What is a UV index widget on iPhone?

A UV index widget is a small Home Screen, Lock Screen, or StandBy tile that displays the current ultraviolet index for your location without you needing to open an app. iOS widgets refresh in the background on a schedule managed by iOS, so the UV reading you see is broadly current — typically within the past 15 minutes. The widget itself is provided by a UV forecast app (such as Sunwise or Apple's Weather app), and the level of detail it shows depends on the app and the widget size you pick.

Does Apple's Weather app have a UV index widget?

The Apple Weather widget shows the current condition and temperature but does not have a dedicated UV index widget on iOS. To put the UV index — not just temperature — on your Home Screen or Lock Screen, you need a third-party UV forecast app that ships its own widget. Sunwise provides UV-first widgets: Home Screen widgets for the current UV index, the hourly curve and the 7-day outlook, and Lock Screen widgets that include a personalized burn time.

Can I add a UV index widget to my iPhone Lock Screen?

Yes. iOS 16 and later supports Lock Screen widgets in three shapes — inline (a single line of text above the clock), circular, and rectangular. To add a UV index Lock Screen widget, long-press the Lock Screen, tap Customize, tap a widget slot, and pick the UV forecast app's widget. Inline widgets work well for a single UV number and risk level; in the circular and rectangular slots, Sunwise offers both UV index widgets and a Burn Time widget that shows how long until you'd burn.

What is a StandBy UV widget?

StandBy is the full-screen widget view iOS 17 introduced that activates when an iPhone is charging in landscape orientation. A StandBy UV widget displays the current UV index on the larger surface, which is useful for bedside or desk docking. StandBy uses Home Screen small widgets, so Sunwise's Current UV widget shows the UV index, its risk level, and the day's peak UV at a glance — comfortable to read from a few feet away. Burn time lives on the Lock Screen and Apple Watch.

What should a good UV index widget show?

A glanceable UV widget should answer 'is the sun safe right now?' without the user opening the app. That means three things: the current UV index, how high UV will peak today, and how long the user can safely stay outside (the burn time). A widget that only shows the UV number is missing the most actionable part of the answer — your safe exposure window depends on your skin type, not just the UV level.

Do UV index widgets drain the battery?

Not noticeably. iOS controls how often widgets are allowed to refresh — typically every 15–30 minutes — so the UV widget is not constantly polling for new data. A UV widget that uses your location uses the same background-location service as the parent app, which is also rate-limited by iOS. In practice, adding a UV widget has no perceptible impact on iPhone battery life.

How is the Sunwise UV widget different from UV Index Widget - Worldwide?

Both apps provide a UV index widget for iPhone. The key difference is personalization: Sunwise's Lock Screen Burn Time widget shows a burn time calculated for your Fitzpatrick skin type, so it answers 'how long can I stay in the sun?' rather than just displaying a number. Sunwise also ships native Apple Watch complications, Lock Screen widgets, and Home Screen widgets for the hourly curve and 7-day outlook, while UV Index Widget - Worldwide is primarily Home Screen widget focused. Both apps draw forecast data from reputable sources — Sunwise uses Apple WeatherKit.

UV Index Widget for iPhone: Home Screen, Lock Screen & StandBy

An iPhone UV index widget puts the current UV level on your Home Screen, Lock Screen, or StandBy face so you don't have to open the Weather app or remember to check. iOS supports widgets in three surfaces — and the right one to use depends on whether you want a passing glance, a planning surface, or a bedside-clock view. This guide covers how to add a UV index widget to each surface, what makes a useful widget design, and how Sunwise's Lock Screen widgets differ from generic UV index widgets by including a personalized burn time.

By Sunwise · Published May 26, 2026 · Updated October 7, 2026

Where can I put a UV index widget on iPhone?

iOS supports widgets on three main surfaces. The Home Screen has been the home of widgets since iOS 14, the Lock Screen added widgets in iOS 16, and iOS 17 introduced StandBy — a full-screen widget view that activates when an iPhone is on a charger in landscape. A UV forecast app like Sunwise provides widgets for all three.

Surface & size	What the widget shows	Best for
Home Screen — small	Current UV index, risk level, and the day's peak UV	Quick glances. Pairs well with a weather widget next to it; together they cover the day's conditions in one row.
Home Screen — medium	Two widgets: Current UV (UV index, risk level, and the day's peak UV) or Hourly UV (now plus the next 4 hours)	Planning the day. The hourly widget shows whether UV is climbing or falling so you can move outdoor plans to a lower-UV window.
Home Screen — large	A 7-day UV outlook	Weekly planning — useful if you exercise outdoors or want to schedule beach days around a moderate-UV week.
Lock Screen — inline	A single line: 'UV 7 · High'	Minimal Lock Screens. Puts the UV index and its risk level in the slot above the clock without taking visual weight.
Lock Screen — circular	Current UV index on a gauge, or your burn time	Quick glances at the watch-face-style circular slot. Add both side by side to see the UV level and how long until you'd burn.
Lock Screen — rectangular	Current UV index with the day's peak UV, the next few hours of UV, or 'Burns in …' with your burn time	Seeing your burn time on the Lock Screen without unlocking. Best used in the rectangular slot below the clock.
StandBy (iOS 17+)	The small Home Screen widget: UV index, risk level, and the day's peak UV	Bedside or desk docking. Glanceable from across the room — useful in summer for a 'should I go outside now?' check.

How to add a UV index widget to your iPhone Home Screen

1.Install a UV forecast app with widget support — for example Sunwise. Open the app once so iOS registers its widgets.
2.Press and hold any empty area of your Home Screen until the icons start to wiggle.
3.Tap the plus (+) button in the top-left corner to open the widget gallery.
4.Search for the UV app and swipe through the available sizes — small, medium, and large. Each size shows more information than the last.
5.Tap Add Widget, drag it to where you want it on the Home Screen, then tap Done.

On iPad, the same flow works in landscape — iPadOS also supports widgets in the Today View at the left edge of the Home Screen. For a deeper look at how widgets fit into the broader Apple ecosystem, see our Apple Watch UV index guide for the equivalent on watchOS.

How to add a UV index widget to the iPhone Lock Screen

Lock Screen widgets were introduced in iOS 16 and live in two regions: the inline slot above the clock and the four widget slots below the clock. UV is a good fit for both — an inline UV reading is the lightest possible safe-exposure prompt, and in the circular or rectangular slots Sunwise's Burn Time widget shows how long until you'd burn.

1.Wake your iPhone and long-press the Lock Screen. Tap Customize, then pick Lock Screen.
2.Tap the inline slot above the clock or the widget area below the clock to open the widget picker.
3.Find the UV forecast app in the list. Pick an inline, circular, or rectangular widget to match the slot you tapped.
4.Tap Done and then Set as Wallpaper Pair if iOS prompts. Your UV widget now updates on the Lock Screen without unlocking the phone.

How to add a UV index widget in StandBy (iOS 17 and later)

StandBy turns your iPhone into a full-screen widget surface whenever it's charging in landscape — bedside, desk dock, kitchen counter. A UV widget in StandBy is the most glanceable of the three surfaces because it's large enough to read from across the room.

1.Connect your iPhone to a charger and place it on its side in landscape orientation. StandBy launches automatically.
2.Swipe right until you see the widget view (StandBy also has Photos and Clock views).
3.Long-press a widget and authenticate with Face ID. Tap the plus (+) button in the corner to add a new widget.
4.Pick the UV forecast app from the list. The widget joins the StandBy rotation and surfaces automatically based on time of day.

StandBy is particularly useful in summer: a glance from across the room tells you the current UV level and how high it will peak today. For your burn time, add Sunwise's Burn Time widget to the Lock Screen.

What makes a good UV index widget?

A widget's job is to answer a question without opening the app. The right question for a UV widget isn't "what is the UV index?" — it's "is the sun safe right now?". A useful UV widget surfaces three things:

•Current UV index — the real-time value at your GPS location, with WHO color banding so the level is recognisable at a glance.
•Burn time — how long you can stay in the sun based on your Fitzpatrick skin type, in minutes. This is the part that makes a UV reading actionable.
•The day's peak UV — how high UV will get today, so you can plan outdoor activities around it instead of being surprised by midday UV 9.

Most generic UV widgets only show the first item. Sunwise was built around the idea that the UV number alone isn't actionable — a UV index of 7 means very different things for fair (Fitzpatrick Type I–II) skin and darker (Type V–VI) skin, and the burn time captures that. To find your Fitzpatrick type, take the Fitzpatrick skin type quiz. For the meaning of each UV level, see the UV index guide.

How often does an iPhone UV widget update?

iOS controls widget refresh — apps don't get to decide. In practice, a UV widget refreshes roughly every 15–30 minutes under typical conditions, more often if the user has recently interacted with the parent app, and less often if the phone is in Low Power Mode. iOS also batches widget refreshes across installed apps so the system can hit the network efficiently.

For UV that's perfectly fine: UV changes on the order of minutes, not seconds, and the underlying forecast itself is published hourly by most data sources. Sunwise uses Apple WeatherKit, which exposes forecast UV at hourly granularity — so a 15-minute widget refresh is already over-sampling the source data. For more on the data side, see the UV index accuracy guide.

Sunwise UV widget vs UV Index Widget — Worldwide

UV Index Widget — Worldwide is a popular and well-reviewed iPhone widget that surfaces the current UV index for your location. It's a solid choice if a single UV number is what you want from a widget. Sunwise is a different proposition: its widgets show the UV index with the day's peak UV, and its Lock Screen Burn Time widget shows a burn time calculated for your Fitzpatrick skin type — so it answers a more useful question.

Sunwise also ships native Apple Watch complications, Lock Screen widgets in all three iOS 16+ shapes, and Home Screen widgets that also work in StandBy on iOS 17 and later — covering every iOS widget surface rather than only the Home Screen. For a side-by-side comparison of all the main UV apps, see our roundup of the best UV index apps for iPhone, or read how to check the UV index on iPhone for the broader workflow.

FAQ: iPhone UV index widgets

What is a UV index widget on iPhone?: A UV index widget is a small Home Screen, Lock Screen, or StandBy tile that displays the current ultraviolet index for your location without you needing to open an app. iOS widgets refresh in the background on a schedule managed by iOS, so the UV reading you see is broadly current — typically within the past 15 minutes. The widget itself is provided by a UV forecast app (such as Sunwise or Apple's Weather app), and the level of detail it shows depends on the app and the widget size you pick.
Does Apple's Weather app have a UV index widget?: The Apple Weather widget shows the current condition and temperature but does not have a dedicated UV index widget on iOS. To put the UV index — not just temperature — on your Home Screen or Lock Screen, you need a third-party UV forecast app that ships its own widget. Sunwise provides UV-first widgets: Home Screen widgets for the current UV index, the hourly curve and the 7-day outlook, and Lock Screen widgets that include a personalized burn time.
Can I add a UV index widget to my iPhone Lock Screen?: Yes. iOS 16 and later supports Lock Screen widgets in three shapes — inline (a single line of text above the clock), circular, and rectangular. To add a UV index Lock Screen widget, long-press the Lock Screen, tap Customize, tap a widget slot, and pick the UV forecast app's widget. Inline widgets work well for a single UV number and risk level; in the circular and rectangular slots, Sunwise offers both UV index widgets and a Burn Time widget that shows how long until you'd burn.
What is a StandBy UV widget?: StandBy is the full-screen widget view iOS 17 introduced that activates when an iPhone is charging in landscape orientation. A StandBy UV widget displays the current UV index on the larger surface, which is useful for bedside or desk docking. StandBy uses Home Screen small widgets, so Sunwise's Current UV widget shows the UV index, its risk level, and the day's peak UV at a glance — comfortable to read from a few feet away. Burn time lives on the Lock Screen and Apple Watch.
What should a good UV index widget show?: A glanceable UV widget should answer 'is the sun safe right now?' without the user opening the app. That means three things: the current UV index, how high UV will peak today, and how long the user can safely stay outside (the burn time). A widget that only shows the UV number is missing the most actionable part of the answer — your safe exposure window depends on your skin type, not just the UV level.
Do UV index widgets drain the battery?: Not noticeably. iOS controls how often widgets are allowed to refresh — typically every 15–30 minutes — so the UV widget is not constantly polling for new data. A UV widget that uses your location uses the same background-location service as the parent app, which is also rate-limited by iOS. In practice, adding a UV widget has no perceptible impact on iPhone battery life.
How is the Sunwise UV widget different from UV Index Widget - Worldwide?: Both apps provide a UV index widget for iPhone. The key difference is personalization: Sunwise's Lock Screen Burn Time widget shows a burn time calculated for your Fitzpatrick skin type, so it answers 'how long can I stay in the sun?' rather than just displaying a number. Sunwise also ships native Apple Watch complications, Lock Screen widgets, and Home Screen widgets for the hourly curve and 7-day outlook, while UV Index Widget - Worldwide is primarily Home Screen widget focused. Both apps draw forecast data from reputable sources — Sunwise uses Apple WeatherKit.

Put a personalized UV widget on your iPhone

Sunwise is a personalized UV forecast app for iPhone, iPad, and Apple Watch. Its widgets show the current UV index, the day's peak UV, the hourly curve, and the 7-day outlook across Home Screen, Lock Screen, and StandBy surfaces. Set your Fitzpatrick skin type once and the Lock Screen Burn Time widget shows a specific safe-exposure window you can plan around.