Indianapolis, IN UV Index Today
What is the UV index in Indianapolis right now?
0.9 Low
EPA describes low UV as needing no protection for most people.
Today's peak is 6.7 (High) at about 2pm local time.
When is UV strongest in Indianapolis today?
UV in Indianapolis peaks at 6.7 (High) around 2pm local time (GMT-4). It stays at 6 or above — the high band — for 2 hours, roughly 1pm to 3pm. UV is 3 or above for 6 hours.
Indianapolis today, in numbers
- Latitude
- 39.8°N — 55 of 121 from the north
- Today's peak
- 6.7 (High) — 63 of 121 nationally
- Peak arrives
- 2pm local (GMT-4)
- At or above 6
- 2 hours, 1pm to 3pm
- At or above 3
- 6 hours, 11am to 5pm
The window from 1pm to 3pm is the practical answer for Indianapolis 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 →
Denver's latitude, minus the altitude and the clock
Indianapolis and Denver sit within a tenth of a degree of the same latitude, 39.8 and 39.7 north. The sun does exactly the same thing above both cities on the same date. Everything separating their readings is underneath it: Denver is a mile up in dry, thin air, while Indianapolis sits at about 715 feet with the full depth of a humid continental atmosphere in the way. Identical solar geometry, a different amount of air for the light to cross.
The clock separates them too, and by more. The 105th meridian that Mountain time is built on runs through Denver, so its solar noon and its clock noon agree to within about a minute. Indianapolis keeps Eastern time from more than eleven degrees west of the 75th meridian, which pushes its solar noon roughly three quarters of an hour late — near 12:45 in standard time, near 1:45 under daylight saving. Two cities under an identical sun angle reach their daily maximum forty-five minutes apart by their own clocks.
Winter and summer catch people out in opposite directions here. At the December solstice the noon sun climbs to under 27 degrees, so even a bright day delivers little. July runs the other way: a humid sky can go flat white with haze that scatters light in every direction rather than absorbing it, which means a dull-looking afternoon is not on its own evidence of a low reading.
Nearest metros we model
What does Indianapolis’s UV index mean today?
0.9 is Low. EPA describes low UV as needing no protection for most people. Today Indianapolis 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 Indianapolis 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 Indianapolis
What is the UV index in Indianapolis today?
When is UV strongest in Indianapolis today?
Is this measured or modelled?
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