UV index in Miami in August
In August, the UV index in Miami typically peaks around 8.3 at midday — very high on the WHO scale — with individual days reaching 9 in recent years. Sun protection is needed around the middle of the day.
How fast would you burn?
Estimated time to sunburn in unprotected midday sun at UV 8.3:
| Skin type | Time to burn |
|---|---|
| I — Very fair | ~16 min |
| II — Fair | ~20 min |
| III — Medium | ~28 min |
| IV — Olive | ~36 min |
Estimates from typical minimal erythemal doses — see methodology. Darker types (V–VI) burn slower still. Reflection off water or sand shortens all of these.
What to do about it
- Treat midday sun as hostile: SPF 50, a real hat, UV-blocking sunglasses, and shade between 11am and 3pm.
- Fair skin (types I–II) can burn in 15–25 minutes at these levels — reapply sunscreen strictly every 2 hours.
- UPF-rated clothing outperforms sunscreen for long days out — consider a sun shirt for beach or boat days.
Planning a trip? Check the live UV index in Miami closer to your dates — day-to-day cloud cover moves the real number around this average.
Miami's UV year at a glance
| Month | Typical midday peak | Level |
|---|---|---|
| January | 4.6 | Moderate |
| February | 6.2 | High |
| March | 7.4 | High |
| April | 8.5 | Very high |
| May | 8.8 | Very high |
| June | 7.8 | High |
| July | 8.4 | Very high |
| August | 8.3 | Very high |
| September | 7.5 | High |
| October | 6.5 | High |
| November | 5.5 | Moderate |
| December | 4.7 | Moderate |
The strongest month is May (typical peak 8.8); the gentlest is January (typical peak 4.6).
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