United States
Get the app
UV index · Boston

UV index Boston today: right now and hour by hour

Now 0 low
Max today 3.2 around 11 AM
Max tomorrow 0.8 around 12 PM

UV index in Boston right now: 0 — the sun isn't up yet. Today it is forecast to peak at 3.2 (moderate) around 11 AM. Today the UV index in Boston is 3 or higher from 10 AM to 1 PM — the hours when the WHO recommends sun protection.

4.6 ★ on the App Store · free
UV index card in the app: today's hourly bars, peak 6.4, “Now moderate, protection needed”

In the Weather24 app

When does UV peak where you are?

The UV index card with today's peak, hour by hour, and a line that says whether you need protection right now.

Download on theApp Store Get it onGoogle Play

UV index in Boston: today and tomorrow · Max today 3.2

Each bar is one hour, in WHO colors. The thin line shows the UV index under a clear sky — clouds bring the real value below it. Hourly values from a weather model, local time; updated every hour.

0 1 2 3 4 5 3.2 · 11 AM 6AM12PM6PM6AM12PM6PM todaytomorrow 0 1 2 3 4 5 3.2 · 11 AM 6AM12PM6PM6AM12PM6PM todaytomorrow
UV clear sky protection from 3 night
Boston

UV index in Boston by month: about 8 in June, 3 in November

In November the typical daily UV maximum in Boston is about 3 — the last month of the season with 3 or more. After that it usually stays below 3 until February and peaks at about 8 in June.

2 Jan 4 Feb 5 Mar 6 Apr 7 May 8 Jun 8 Jul 7 Aug 6 Sep 4 Oct 3 Nov 2 Dec 2 Jan 4 Feb 5 Mar 6 Apr 7 May 8 Jun 8 Jul 7 Aug 6 Sep 4 Oct 3 Nov 2 Dec

Typical daily UV maximum for each month: the median of hourly model values over the last three years (Nov 2023 – Oct 2026, Open-Meteo). Sunny days run higher, overcast days lower.

Sun in Boston today: 10 h 10 min of daylight

The UV index is highest around solar noon, when the sun is at its highest — in Boston today around 11:27. The day is 10 h 10 min long; at the June solstice it lasts 15 h 17 min, at the December solstice 9 h 4 min.

Sunrise06:22
Sunset16:32
Sun highest11:27
Day length10 h 10 min

UV index in the Weather24 app

On the Today screen the UV index card shows today's maximum and its level. Tap it for UV hour by hour with the peak and a line that says whether you need protection right now. UV is also in the rows under the hourly forecast — for your location and every saved city.

Download on theApp Store Get it onGoogle Play
Scan to install
4.6 ★ on the App Store · free

Frequently asked questions

What is the UV index today in Boston?
UV index in Boston right now: 0 — the sun isn't up yet. Today it is forecast to peak at 3.2 (moderate) around 11 AM. Today the UV index in Boston is 3 or higher from 10 AM to 1 PM — the hours when the WHO recommends sun protection.
What time is the UV index highest in Boston?
Today the highest hourly value is 3.2 around 11 AM. The UV index peaks around solar noon, when the sun is highest; the hourly chart above shows the whole day.
What is the UV index tomorrow in Boston?
Tomorrow's forecast maximum is 0.8 (low) around 12 PM. Hour by hour it's in the second half of the chart above.
When does the UV index go above 3 in Boston?
In November the typical daily UV maximum in Boston is about 3 — the last month of the season with 3 or more. After that it usually stays below 3 until February and peaks at about 8 in June.
Where does the data come from?
From a weather model via Open-Meteo (CC BY 4.0), hour by hour. These are model values for a point in the city, not readings from a station. The official UV Index forecast in the US is published by the EPA with the National Weather Service.

UV index in other cities

UV index New YorkUV index PhiladelphiaUV index Washington, DCUV index Detroit UV index across US →

See also: UV index scale: what each level means · barometric pressure today · rain radar