Live UV index · Tanning timer · Vitamin D

Know exactly when to get out of the sun.

Sunhalo tells you the one thing your weather app won't. Set your skin type once — get the live UV index where you're standing, an SPF-aware protection timer, and reminders to reapply, take shade, and reassess.

Download on theApp Store See how it works
Livehourly UV forecast
FreeUV, timer & coaching
Privatephotos stay on device
UV Index & Tanning — check local UV now and plan smarter sun exposure with Sunhalo
Exact-location UV SPF-aware timer Vitamin D estimates Sun compass Home Screen widgets No base-tan myths
How it works

Three taps to a smarter day in the sun

Sunhalo turns raw UV numbers into a plan built around your skin and the SPF you're actually wearing.

1
🧑‍🦰

Set your skin type once

Pick your Fitzpatrick skin type and how you usually cover up. It's the only setup — everything else is automatic.

2
📍

Get live UV where you stand

Sunhalo pulls the real-time UV index and hourly forecast for your exact location, not a city average.

3
⏱️

Follow your protection timer

A conservative reassessment estimate tells you when to reapply, take shade, and check back — even from your Lock Screen.

Protection plan

A live UV index that actually tells you what to do

Your weather app shows a number. Sunhalo shows the number and the plan: risk level, SPF guidance, and your protection window for the day.

  • Live UV index and hourly forecast for your precise location
  • Personal reassessment estimate from skin type, live UV and labeled SPF
  • Session coaching: turn reminders, reapply prompts, shade breaks
  • Lock Screen countdown that runs while your phone's in your bag
Live UV index screen with a UV risk badge, hourly UV timeline and today's protection window
Vitamin D

Track vitamin D from sunlight — without the guesswork

Sunhalo estimates the IU you make each session from your skin type, exposed skin, SPF and the live UV index, so you can balance a healthy dose against burn risk.

  • Per-session IU estimates using UV, skin type, exposure and SPF
  • Daily goal and weekly totals at a glance
  • Log incidental sun in seconds
Vitamin D screen estimating daily IU from UV index, skin type and SPF
Sun Seeker

Find the sun — and find better shade

A live compass shows exactly where the sun sits right now, which way to face for even exposure, and your morning and evening golden-hour windows.

  • Real-time sun position compass with altitude
  • Golden hour windows for gentler, flattering light
  • Guidance on which way to turn for even coverage
Sun Seeker compass showing the sun's live position with strongest exposure direction and golden hour windows
Glow journal & widgets

Your progress, private — and always one glance away

Save skin tone, before-and-after photos and streaks in a journal that never leaves your device. Keep the UV index, protection window and golden hour on your Home Screen and Lock Screen.

  • Private tanning journal — photos stay on your iPhone
  • History across week, month and year
  • Home Screen UV widget + Lock Screen Live Activity countdown
Glow journal showing skin tone range, before and after photos and a progress calendar
Take the tour

Everything you need for a smarter tan

Swipe through Sunhalo's live UV, vitamin D, sun compass, journal, widgets and Learn hub.

Live UV index right now
Live UV index
Burn risk protection timer
Burn risk timer
Track vitamin D from sunlight
Vitamin D tracker
Sun Seeker compass for safer sun exposure
Sun Seeker compass
Tanning progress glow journal
Glow journal
UV index Home Screen widgets
Home Screen widgets

Love the sun. Respect it.

Live UV, the protection timer and session coaching are free forever. Download Sunhalo and get a plan built around your skin in under a minute.

Download on theApp Store
Sun & tanning guides

The answers people actually search for

Straight, research-backed answers to the biggest sun and tanning questions — and how Sunhalo helps you act on them.

Tanning

What's the best UV index for tanning?

The range that balances colour against burn risk — and how to time it.

Read guide Myth check

Can you tan without burning?

What the science says about tanning safely, and where the limit really is.

Read guide Sunscreen

Does SPF stop you tanning?

Why sunscreen slows burning far more than it stops a tan.

Read guide Safety

Do you need sunscreen on cloudy days?

How much UV actually gets through clouds — usually more than you think.

Read guide Health

How much sun for vitamin D?

Balancing a healthy vitamin D dose against skin damage.

Read guide How-to

How to tan safely

A simple, sunburn-free routine using UV, skin type and SPF.

Read guide Reference

What UV index is safe? The scale explained

What each level from 0 to 11+ means for your skin.

Read guide How-to

When should you reapply sunscreen?

The real rule for reapplication — and how to never forget.

Read guide
FAQ

Sunhalo, answered

Is Sunhalo free?
Yes. The live UV index, the SPF-aware protection timer and session coaching are free forever. Sunhalo Pro is an optional subscription that unlocks the vitamin D tracker, Sun Seeker compass, journal, history and Lock Screen Live Activities. Download free.
How accurate is the UV index in Sunhalo?
Sunhalo uses live UV data and hourly forecasts for your exact location rather than a city-wide average. Readings are educational estimates — altitude, reflection off water, sand and snow, and cloud cover all affect your real exposure. Learn more about the UV scale.
Can I tan safely with Sunhalo?
Sunhalo helps you tan more slowly and avoid burning by pairing live UV with your skin type and SPF, then flagging when to reassess. It never pretends a tan is damage-free. Learn more about tanning safely.
Does Sunhalo really track vitamin D?
It estimates the vitamin D (IU) you produce each session from UV index, skin type, exposed skin and SPF, with daily and weekly totals. It's a model, not a blood test. Learn more about vitamin D from sun.
Does the protection timer work in the background?
Yes. The timer runs as a Lock Screen Live Activity and countdown, so it keeps going while your phone is in your bag and pings you to reapply or seek shade. Learn more about reapplying.
Are my photos and journal private?
Completely. Your glow-journal photos and history stay on your device — they never leave your iPhone. Learn more about the journal.
Does sunscreen stop me from tanning?
No — properly applied SPF dramatically slows burning but still lets some UV through, so you can tan gradually with far less damage. Learn more about SPF and tanning.
Do I need Sunhalo on cloudy days?
Yes. Up to 80% of UV can pass through light cloud, so the index — and your burn risk — can stay high even when it feels overcast. Learn more about cloudy-day UV.