# Stockton, CA UV Index Today — hourly UV forecast

> Source: https://breathecheck.com/uv-index/us/california/stockton/
> UV index in Stockton, CA right now, today's peak and the hour it arrives, on the EPA scale. Modelled data, labelled as modelled.

# Stockton, CA UV Index Today

Modelled for 14 Sep 2026, 22:00 UTC · GMT-7

## What is the UV index in Stockton right now?

4.5 Moderate

EPA suggests shade around midday, a hat and sunglasses.

Today's peak is 6.7 ( High ) at about 1pm local time.

## When is UV strongest in Stockton today?

UV in Stockton peaks at 6.7 (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.

## Stockton today, in numbers

- **Latitude**: 38.0°N — 73 of 121 from the north

- **Today's peak**: 6.7 (High) — 68 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 Stockton 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 coast's sun angle, the valley's sky

San Francisco lies about 60 miles west of Stockton and under a fifth of a degree of latitude south, which puts the sun at effectively the same height over both cities at the same hour on the same date. Their clear-sky potential is identical. What separates the two readings is cloud. Coastal summer afternoons are often spent under marine stratus, while here the July and August rainfall normals round to zero and the sky over the valley floor stays open for weeks at a stretch. Through the summer half of the year, the difference between a Bay Area forecast and this one is a cloud story rather than a sun story.

Winter turns the pair around. Tule fog is a valley phenomenon rather than a coastal one: it pools on the floor here once the season’s first soaking rains have wet the ground, which is what the November-to-March stretch supplies. On a day it does not lift, midday here can read below what the same sun angle is delivering 60 miles west. The geometry is identical in both seasons. The sky is what changes sides.

## 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.

## What does Stockton’s UV index mean today?

4.5 is Moderate. EPA suggests shade around midday, a hat and sunglasses. Today Stockton 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 Stockton 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 Stockton

**What is the UV index in Stockton today?**

4.5 right now (Moderate), peaking at 6.7 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 Stockton 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.

## Related

On this page

Air quality alerts

We alert on AQI, not UV — UV is predictable from the calendar, air quality is not.

Updated 14 Sep 2026, 22:00 UTC