Miami, FL UV Index Today
What is the UV index in Miami right now?
0.6 Low
EPA describes low UV as needing no protection for most people.
Today's peak is 9.2 (Very High) at about 1pm local time.
When is UV strongest in Miami today?
UV in Miami peaks at 9.2 (Very High) around 1pm local time (GMT-4). It stays at 6 or above — the high band — for 4 hours, roughly 12pm to 4pm. UV is 3 or above for 7 hours.
Miami today, in numbers
- Latitude
- 25.8°N — 119 of 121 from the north
- Today's peak
- 9.2 (Very High) — 5 of 121 nationally
- Peak arrives
- 1pm local (GMT-4)
- At or above 6
- 4 hours, 12pm to 4pm
- At or above 3
- 7 hours, 10am to 5pm
The window from 12pm to 4pm is the practical answer for Miami today. Nationally today the spread runs 11.4 in Hilo (20°N) to 1.3 in Fargo (47°N). Why latitude and the clock decide this →
Why the coast keeps the sun the interior loses
Miami’s ultraviolet on any given day is decided less by the calendar than by which way the wind is blowing. Through the wet season, May into October, the prevailing easterly flow off the Atlantic carries the sea breeze straight over the city and organizes the day’s convection well inland of it. The storms that end an afternoon tend to build over the Everglades and western Miami-Dade first. On a typical wet-season day the coastal strip can run its full course under open sky while the interior has already gone dark.
The geometry underneath that is unusual for the mainland. At 25.8 degrees north the sun passes within about two and a half degrees of straight overhead in late June, so at midday it stands very nearly vertical and the path its light takes through the atmosphere is close to the shortest it can be. Shade behaves accordingly. An umbrella or a palm casts almost straight down and covers a smaller patch of ground here in July than the same object does farther north.
The last factor is what is underfoot. Pale sand and the shallow, bright water of Biscayne Bay return part of the incoming ultraviolet upward, so the barrier beaches and the bayfront take a share from below that neighborhoods a few miles inland do not. Stack that against a near-vertical July sun and the same posted number describes two fairly different afternoons depending on which side of the bay you spend it on.
Nearest metros we model
What does Miami’s UV index mean today?
0.6 is Low. EPA describes low UV as needing no protection for most people. Today Miami also reaches Very High at its peak — a different band from the one it is in right now, which is why the hour matters as much as the day.
Modelled, not measured
The UV figures for Miami are computed by the Copernicus atmosphere model, not read off an instrument here — unlike the AQI on our air-quality pages, which comes from a regulatory monitor. Cloud is where a UV model is weakest. What that means in practice →
Questions about UV in Miami
What is the UV index in Miami today?
When is UV strongest in Miami today?
Is this measured or modelled?
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