Pittsburgh, PA UV Index Today
What is the UV index in Pittsburgh right now?
0.5 Low
EPA describes low UV as needing no protection for most people.
Today's peak is 6 (High) at about 1pm local time.
When is UV strongest in Pittsburgh today?
UV in Pittsburgh peaks at 6 (High) around 1pm local time (GMT-4). It stays at 6 or above — the high band — for 1 hour, roughly 1pm to 2pm. UV is 3 or above for 5 hours.
Pittsburgh today, in numbers
- Latitude
- 40.4°N — 50 of 121 from the north
- Today's peak
- 6 (High) — 82 of 121 nationally
- Peak arrives
- 1pm local (GMT-4)
- At or above 6
- 1 hour, 1pm to 2pm
- At or above 3
- 5 hours, 11am to 4pm
The window from 1pm to 2pm is the practical answer for Pittsburgh 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 →
Cloud cover, not latitude, sets the number here
Pittsburgh sits on nearly the parallel of Philadelphia and New York, at 40.4 degrees north, and solar geometry alone would hand it their UV year. Cloud takes it back. WorldAtlas, ranking on long-term NOAA averages, puts the city at about 2,021 hours of sunshine a year, the fewest of any major US city, and attributes that to the northern jet stream sitting over western Pennsylvania through much of the year and to Pittsburgh being close enough to Lake Erie for a share of lake-effect overcast. December is the worst of it, with the sun showing on as few as eight days in the month.
Terrain subtracts a second, smaller amount. The city is cut by the Allegheny, Monongahela and Ohio valleys, running from about 710 feet at the Point to 1,255 feet at Grandview Park on Mount Washington. Steep north-facing slopes shorten the span of the day a given street sees direct sun, which bites hardest in December, when the noon sun clears only about 26 degrees. Fort Collins, at the same latitude for practical purposes, is a mile higher under a far thinner sky and records a completely different year from the same solar input.
One timing note. At almost exactly 80 degrees west, Pittsburgh lies five degrees west of the meridian Eastern Time is built on, so mean solar noon falls roughly 20 minutes after clock noon. The summer peak lands nearer 1:20 in the afternoon than 1:00.
Nearest metros we model
What does Pittsburgh’s UV index mean today?
0.5 is Low. EPA describes low UV as needing no protection for most people. Today Pittsburgh 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.
Modelled, not measured
The UV figures for Pittsburgh 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 Pittsburgh
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