UV index in Boston
Massachusetts, United States · typical UV by month
Today's UV in Boston
The hourly forecast and the lower-UV times for what you do outside. Free, no account needed.
The year at a glance
- UV in Boston is highest in July, when a typical day peaks around 6 (High).
- On a typical July day, UV is 3 or more from about 9am to 5pm, about 6 hours.
- The typical midday UV reaches 3 or more from March to October, when public-health guidance recommends sun protection.
- UV usually stays under 3 from November to February.
- Clouds take the most off in May: a typical peak of 5, against 7 under a clear sky. On a clear day, expect the higher number.
Typical UV by month
The highest UV index of a typical day, with clouds and under a clear sky, and the hours UV is usually 3 or more, from 2023 to 2025.
| Month | Typical peak | Clear sky | UV 3 or more |
|---|---|---|---|
| JanJanuary | 1 Low | 2 | Rarely |
| FebFebruary | 2 Low | 3 | Rarely |
| MarMarch | 3 Moderate | 4 | 11am-3pm |
| AprApril | 4 Moderate | 6 | 10am-4pm |
| MayMay | 5 Moderate | 7 | 9am-4pm |
| JunJune | 6 High | 8 | 9am-5pm |
| JulJuly | 6 High | 8 | 9am-5pm |
| AugAugust | 6 High | 7 | 10am-4pm |
| SepSeptember | 4 Moderate | 6 | 10am-4pm |
| OctOctober | 3 Moderate | 4 | 11am-2pm |
| NovNovember | 2 Low | 2 | Rarely |
| DecDecember | 1 Low | 1 | Rarely |
About these numbers
Averages of every day from 2023 to 2025 in the global atmospheric composition model of the Copernicus Atmosphere Monitoring Service, served by the Open-Meteo Air Quality API (CC BY 4.0), for the city center, in local time. They describe a typical day, not any one day: the UV on a given day can be higher or lower, so check the forecast before you go. Solara is a planning aid, not medical advice.