# Scottsdale, AZ UV Index Today — hourly UV forecast > Source: https://breathecheck.com/uv-index/us/arizona/scottsdale/ > UV index in Scottsdale, AZ right now, today's peak and the hour it arrives, on the EPA scale. Modelled data, labelled as modelled. # Scottsdale, AZ UV Index Today Modelled for 17 Aug 2026, 01:00 UTC · GMT-7 ## Right now 0 Low No protection needed for most people. Today's peak is 10.4 (Very High) at about 12pm local time. ## Hour by hour today Local time, midnight to midnight. Bar colour is the EPA UV band, never restyled. ## Scottsdale today, in numbers - **Latitude**: 33.5°N — 100 of 121 from the north - **Today's peak**: 10.4 (Very High) — 13 of 121 nationally - **Peak arrives**: 12pm local (GMT-7) - **At or above 6**: 6 hours, 10am to 4pm - **At or above 3**: 8 hours, 9am to 5pm The window from 10am to 4pm is the practical answer for Scottsdale today. Nationally today the spread runs 11.7 in Honolulu (21°N) to 0.8 in Anchorage (61°N). Why latitude and the clock decide this → ## A third of the city has no canopy The McDowell Sonoran Preserve is planned at roughly 36,000 acres, close to a third of Scottsdale’s land area, and it is open desert with a trail network through it rather than parkland with trees in it. Sonoran vegetation is built on spacing. Saguaro, palo verde and creosote stand apart from one another and leave gaps instead of closing over, so shade on a Preserve trail at midday is thin, broken and always moving, and the amount of it changes very little between February and August. The other thing this municipality has is vertical range. Its southern boundary is the Salt River on the valley floor; the McDowell Mountains along its eastern edge top out at 4,057 feet at East End. Air cools as it rises and ultraviolet does the opposite, so the higher a trail climbs the more comfortable the air gets and the stronger the light landing on it. Temperature is the cue most people navigate an afternoon by, and across this particular gradient temperature points the wrong way. Neither of those shows up in one figure measured somewhere down on the flat, which is where the instruments are. ## 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. ## Where Scottsdale sits on the scale 0 is Low. No protection needed for most people. Today Scottsdale 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 Scottsdale 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 Scottsdale **What is the UV index in Scottsdale today?** 0 right now (Low), peaking at 10.4 around 12pm local time. UV stays at 6 or above for 6 hours, from about 10am to 4pm. This is a modelled value, not a ground measurement. **When is UV strongest in Scottsdale 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 17 Aug 2026, 01:00 UTC