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Irvine, CA UV Index Today

Modelled for · GMT-7

What is the UV index in Irvine right now?

5.5 High

EPA suggests shade between 10am and 4pm, plus a shirt and sunscreen.

Today's peak is 8.8 (Very High) at about 1pm local time.

When is UV strongest in Irvine today?

UV in Irvine peaks at 8.8 (Very High) around 1pm local time (GMT-7). It stays at 6 or above — the high band — for 4 hours, roughly 11am to 3pm. UV is 3 or above for 7 hours.

Local time, midnight to midnight. Bar colour is the EPA UV band, never restyled.

Irvine today, in numbers

Latitude
33.7°N — 98 of 121 from the north
Today's peak
8.8 (Very High) — 8 of 121 nationally
Peak arrives
1pm local (GMT-7)
At or above 6
4 hours, 11am to 3pm
At or above 3
7 hours, 10am to 5pm

The window from 11am to 3pm is the practical answer for Irvine 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 →

Far Enough Inland To Clear Before Noon

Position on the coastal plain, not latitude, decides how Irvine’s day runs. The city stands several miles back from the water, with the Santa Ana Mountains behind it to the east.

Southern California’s marine layer pushes inland overnight through May and June and covers the plain at dawn. It breaks up as the ground warms, and inland ground warms first, so the deck over Irvine thins and opens earlier in the day than the deck at the shoreline. Regional burn-off falls somewhere between mid-morning and early afternoon; on the inland side of that gradient the sky is usually already open before the sun reaches its highest point. A gray Irvine morning still ends in a high afternoon reading more often than not.

Autumn reverses the mechanism. Offshore Santa Ana flow out of the interior pushes the marine air back out to sea and replaces it with dry desert air, so a fall day can run cloudless from sunrise with no morning deck to burn off at all. December does not fall far here either: at 33.68°N the noon sun still stands about 33 degrees above the horizon at the winter solstice, which leaves a narrower gap between Irvine’s summer peak and its winter one than most of the country runs.

Nearest metros we model

UV changes with latitude, not with a city boundary, so a neighbour a hundred miles north reads differently for a reason.

Anaheim, CA 12 mi · 33.8°N peak 8.8 Long Beach, CA 22 mi · 33.8°N peak 8.8 Riverside, CA 31 mi · 34.0°N peak 9.4

What does Irvine’s UV index mean today?

5.5 is High. EPA suggests shade between 10am and 4pm, plus a shirt and sunscreen. Today Irvine 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.

The scale is open-ended: 11 is where the named bands stop, not the maximum. All five bands, with the EPA guidance for each →

Modelled, not measured

The UV figures for Irvine 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 Irvine

What is the UV index in Irvine today?

5.5 right now (High), peaking at 8.8 around 1pm local time. UV stays at 6 or above for 4 hours, from about 11am to 3pm. This is a modelled value, not a ground measurement.

When is UV strongest in Irvine today?

Around 1pm local time (GMT-7), not at noon — solar noon drifts across a timezone and daylight saving moves it later on the clock.

Is this measured or modelled?

Modelled. The figures come from the Copernicus atmosphere model via Open-Meteo, unlike the AQI on our air-quality pages, which is read from an EPA regulatory monitor. Cloud cover is where a UV model is weakest.

Irvine air qualityThe AQI, from a regulatory monitor rather than a model UV across the USWhere Irvine sits against every metro we track

Updated