Boston, Massachusetts Weather
Apples hang heavy on the branch. Day 93 of summer. Read this microseason across nine climate regions →
Boston weather forecast — hour by hour, 7-day outlook, NOAA radar
Conditions updated 8:50 AM EDT · Open-Meteo
- TodaySep 21Overcast45%0.07″66°55°—
- TuesdaySep 22Overcast——61°54°-5°
- WednesdaySep 23Overcast——61°54°0°
- ThursdaySep 24Overcast23%—63°49°+2°
- FridaySep 25Overcast61%—68°49°+5°
- SaturdaySep 26Overcast63%—72°54°+4°
- SundaySep 27Overcast55%—73°57°+1°
Air quality now AQI 45 · Good
AQI 45 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 6.2 µg/m³, PM10 at 7.8 µg/m³ — typical background levels with no transport signature.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
PM × Wind × Precip
PM2.5 at 6.2 µg/m³, PM10 at 7.8 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.79
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- background
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
September dries up ditches or breaks down bridges.
- Moonrise
- 4:23 PM
- Moonset
- 12:54 AM
- In sign
- ♑︎ Capricorn
Apples hang heavy on the branch
Read this microseason across nine climate regions →
All 72 microseasons on the year wheel →
Boston at a glance
- Today vs. normal: Today averages 61°F (high 66°F, low 55°F), 2°F below the 63°F normal for Sep 21
- Last frost: April 19 (1991–2020 median, NOAA station 4 km away)
- Microseason: Sep 21–25
- Planting calendar: September — plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, winter squash
16-Day Forecast — Boston
- Mon66°55°45%
- Tue61°54°0%
- Wed61°54°1%
- Thu63°49°23%
- Fri68°49°61%
- Sat72°54°63%
- Sun73°57°55%
- Mon68°55°34%
- Tue68°52°13%
- Wed73°53°21%
- Thu73°58°21%
- Fri71°55°15%
- Sat62°51°16%
- Sun73°52°13%
- Mon72°58°19%
- Tue59°45°16%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Boston
Interactive wind and temperature map centered on Boston — it loads in your browser. Open the full weather map.
Right now in the garden
Fall planting + final harvests
As of September 21, the season's first frost (typically October 23) is approaching. Pick what frost-tender plants still carry before the next cold front. This city's planting calendar for September: plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, and winter squash.
Sun & seasons in Boston
Boston sits in Suffolk County, where the year’s longest day runs 15h 17m of daylight and its shortest just 9h 5m — a swing of +6h 12m between the June and December solstices. Clocks spring forward on Sunday, March 8, 2026 and fall back on Sunday, November 1, 2026.
Boston is the state’s largest city. The nearest town Boston tracks is Worcester, roughly 37 miles to the W.
Air quality in Boston
Air quality in Boston’s county has trended cleaner since 2020; its cleanest year on record was 2024 (median AQI 36). See the full air-quality history for Boston.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| March | lettuce, peas, spinach, radishes | — |
| April | lettuce, peas, spinach, radishes | radishes |
| May | tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes |
| July | tomatoes, peppers, beans, squash | lettuce, peas, beans, summer squash, garlic |
| August | beans, squash, fall brassicas, carrots | tomatoes, peppers, beans, summer squash |
| September | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash |
| October | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, carrots |
| November | — | fall brassicas, carrots |
A year in weather
The year in Boston tops out in July (~74°F) and dips lowest in January (~28°F), with December wettest at 5.1 inches and July driest at 3.5 inches.
| Month | Mean temp | Precip |
|---|---|---|
| January | 28° | 3.9″ |
| February | 30° | 3.6″ |
| March | 38° | 4.5″ |
| April | 49° | 4.3″ |
| May | 59° | 3.6″ |
| June | 68° | 4.2″ |
| July | 74° | 3.5″ |
| August | 73° | 3.7″ |
| September | 65° | 4.0″ |
| October | 53° | 5.0″ |
| November | 43° | 4.0″ |
| December | 34° | 5.1″ |
Regional context
Similar climates Cambridge, MA, Somerville, MA, Quincy, MA
Boston's climate, from NOAA NCEI 1991-2020 station normals, pairs 28°F Januarys with 74°F Julys — a 46°F swing. About 49.4 inches of precipitation falls each year.
Boston's precipitation spreads evenly across the seasons: December peaks at 5.1 inches, while July holds 3.5 inches — no season dominates Boston's rain calendar. That lines Boston up with places like Cambridge, MA, Somerville, MA and Quincy, MA, fed by overlapping storm tracks.
By April 19 the frosts ease in Boston, opening the season for kale, peas, spinach, and parsnips. Hold Boston's tender crops — tomatoes, peppers, basil — until 10-14 days past Boston's last frost. Boston's window closes around October 23 as Boston's overnight lows return below freezing. In about half of years, Boston's last freeze comes after April 19.
Similar climates: Cambridge, MA, Somerville, MA, Quincy, MA, Chelsea, MA, Everett, MA.
Frequently asked
- When does it freeze in Boston?
- In Boston, expect the last spring frost near April 19; Boston's first autumn frost comes around October 23.
- What is the rainy season in Boston?
- December is the wettest month in Boston, about 5.1 inches on average; the year totals roughly 49 inches.
- What is the warmest month in Boston?
- Boston peaks in July, when the mean runs near 74°F.
- What is the coldest month in Boston?
- January is Boston's coldest month, averaging about 28°F.
- When can I start a vegetable garden in Boston?
- In Boston, sow peas and hardy greens around April 19; Boston's tomatoes and peppers wait two weeks more.
- What hardiness zone is Boston?
- Since January in Boston averages 28°F, Boston's USDA zone follows that floor — confirm it by ZIP.
- What is the 10-day forecast for Boston?
- Boston's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Boston?
- See this week's day-by-day rain chances for Boston in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Boston?
- Current conditions for Boston and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Boston forecast updated?
- The Boston forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Boston?
- Today's sunrise and sunset times for Boston are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Boston?
- The next few days in Boston's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Boston sits at 42.3°N; its climate zone is warm-summer humid continental (Köppen approximation).
ZIP codes in Boston
- 02108
- 02109
- 02110
- 02111
- 02112
- 02113
- 02114
- 02115
- 02116
- 02117
- 02118
- 02119
- 02120
- 02121
- 02122
- 02123
- 02124
- 02125
- 02126
- 02127
- 02128
- 02129
- 02130
- 02131
- 02132
- 02133
- 02134
- 02135
- 02136
- 02137
- 02163
- 02196
- 02199
- 02201
- 02203
- 02205
- 02206
- 02210
- 02211
- 02212
- 02215
- 02217
- 02222
- 02241
- 02283
- 02284
- 02293
- 02297
- 02298
- 02467