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Sacramento, CA UV Index Today

Modelled for · GMT-7

What is the UV index in Sacramento right now?

4.6 Moderate

EPA suggests shade around midday, a hat and sunglasses.

Today's peak is 6.8 (High) at about 1pm local time.

When is UV strongest in Sacramento today?

UV in Sacramento peaks at 6.8 (High) around 1pm local time (GMT-7). It stays at 6 or above — the high band — for 3 hours, roughly 12pm to 3pm. UV is 3 or above for 6 hours.

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

Sacramento today, in numbers

Latitude
38.6°N — 68 of 121 from the north
Today's peak
6.8 (High) — 59 of 121 nationally
Peak arrives
1pm local (GMT-7)
At or above 6
3 hours, 12pm to 3pm
At or above 3
6 hours, 10am to 4pm

The window from 12pm to 3pm is the practical answer for Sacramento 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 →

The delta breeze cools the evening, not the sun

The thing most likely to mislead a reader here works by feel rather than by number. The delta breeze — marine air pulled in through the Carquinez Strait as the valley heats through the day — typically reaches Sacramento between six and nine in the evening from June through September. It arrives hours after the sun has crossed its highest point, and the sky ahead of it is usually clear. A comfortable evening here is not evidence about what the middle of the day did.

Sacramento stands at the confluence of the Sacramento and American rivers, close to sea level, on ground flat enough that no local relief shades any part of it. What separates its summer from an eastern city at the same sun angle is not the terrain but the near-total absence of cloud from May into September.

The winter half runs on a different mechanism. Sacramento falls in the northern reach of the tule fog belt, a ground-level radiation fog that forms after the first heavy rains and can lie over the valley for days at a time. Under a fog that does not lift, midday collapses to almost nothing, and the distance between a foggy December day and a clear one at the same date is far wider than the calendar would suggest.

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.

Stockton, CA 44 mi · 38.0°N peak 6.7 Oakland, CA 69 mi · 37.8°N peak 6.7 San Jose, CA 88 mi · 37.3°N peak 7.2

What does Sacramento’s UV index mean today?

4.6 is Moderate. EPA suggests shade around midday, a hat and sunglasses. Today Sacramento also reaches 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 Sacramento 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 Sacramento

What is the UV index in Sacramento today?

4.6 right now (Moderate), peaking at 6.8 around 1pm local time. UV stays at 6 or above for 3 hours, from about 12pm to 3pm. This is a modelled value, not a ground measurement.

When is UV strongest in Sacramento 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.

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

Updated