# Portland, OR UV Index Today — hourly UV forecast > Source: https://breathecheck.com/uv-index/us/oregon/portland/ > UV index in Portland, OR right now, today's peak and the hour it arrives, on the EPA scale. Modelled data, labelled as modelled. # Portland, OR UV Index Today Modelled for 14 Sep 2026, 22:00 UTC · GMT-7 ## What is the UV index in Portland right now? 2 Low EPA describes low UV as needing no protection for most people. Today's peak is 3.8 ( Moderate ) at about 12pm local time. ## When is UV strongest in Portland today? UV in Portland peaks at 3.8 (Moderate) around 12pm local time (GMT-7). It does not reach the high band at any hour today. UV is 3 or above for 2 hours. Local time, midnight to midnight. Bar colour is the EPA UV band, never restyled. ## Portland today, in numbers - **Latitude**: 45.5°N — 9 of 121 from the north - **Today's peak**: 3.8 (Moderate) — 112 of 121 nationally - **Peak arrives**: 12pm local (GMT-7) - **At or above 6**: not today - **At or above 3**: 2 hours, 12pm to 2pm Portland never reaches the high band today; the midday hours still warrant a hat. 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 → ## One Short Season Carries The Whole Year Portland’s day length swings by nearly seven hours between the solstices. At 45.52°N, the June solstice runs 15 hours and 41 minutes, from a 5:21 a.m. sunrise to a 9:03 p.m. sunset; the December one runs 8 hours and 42 minutes. Cloud reinforces that swing instead of softening it. Portland is among the cloudiest American cities in winter, with heavy cloud on roughly three of every four winter days, so from November into March the index stays low almost without exception. Then the summer ridge builds over the eastern Pacific, the storm track moves north with it, and the region turns genuinely dry at the same time the days are longest. The year’s entire ultraviolet budget is compressed into a few months rather than spread across twelve. The afternoon also runs late on the clock. Portland lies nearly three degrees west of the 120th meridian that sets Pacific time, which puts solar noon around ten past one in daylight time. The peak arrives later than someone from the eastern half of the country would expect, and a July evening holds usable sun long past the hour it has gone dim elsewhere. ## 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 Portland’s UV index mean today? 2 is Low. EPA describes low UV as needing no protection for most people. Today Portland also reaches Moderate 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 Portland 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 Portland **What is the UV index in Portland today?** 2 right now (Low), peaking at 3.8 around 12pm local time. It does not reach the high band today. This is a modelled value, not a ground measurement. **When is UV strongest in Portland today?** Around 12pm 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