Boston, Massachusetts Weather
Fireflies rise from the lawn. Day 78 of spring. Read this microseason across nine climate regions →
Boston weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 5Overcast——89°63°—
- SaturdayJun 6Light Drizzle20%—92°66°+3°
- SundayJun 7Light Showers83%0.01″81°59°-11°
- MondayJun 8Overcast30%—78°53°-3°
- TuesdayJun 9Overcast——88°59°+10°
- WednesdayJun 10Overcast——92°65°+4°
- ThursdayJun 11Overcast20%—95°66°+3°
AQI 62 (Moderate), driven by PM2.5. AQI down 34 over the last 6 hours — air quality is improving sharply. PM2.5 at 8.0 µg/m³, PM10 at 9.3 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
Ozone × UV × Sky
Ozone at AQI 39. Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.
- Present
- AQI 39
- UV peak
- 3.3 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 9
PM × Wind × Precip
PM2.5 at 8.0 µg/m³, PM10 at 9.3 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.86
- 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).
The higher the clouds, the finer the weather.
- Moonrise
- 3:50 AM
- Moonset
- 1:42 PM
- In sign
- ♒︎ Aquarius
Fireflies rise from the lawn
Boston at a glance
- Today vs. normal: 6°F below the seasonal normal for this latitude
- Last frost: April 30 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 5, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
SPC Convective Outlook
Storm Prediction Center — Boston
SPC has placed Boston in the Marginal Risk category for severe thunderstorms day after tomorrow.
- TODAYNONENo severe risk
- TOMORROWNONENo severe risk
- DAY 3MRGLMarginal Risk
Isolated severe storms possible. Limited threat for hail or damaging wind.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | — | — |
| May | lettuce, peas, spinach, radishes | lettuce, peas, radishes |
| June | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | tomatoes, peppers, beans, squash, fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | — | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
July ranks as Boston's warmest month with mean temperatures around 74°F, while January stands as the coldest at roughly 28°F. December brings peak rainfall at 5.1 inches, contrasting with July's lighter 3.5 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 28° | 3.9″ | 13 |
| February | 30° | 3.6″ | 12 |
| March | 38° | 4.5″ | 15 |
| April | 49° | 4.3″ | 14 |
| May | 59° | 3.6″ | 12 |
| June | 68° | 4.2″ | 14 |
| July | 74° | 3.5″ | 12 |
| August | 73° | 3.7″ | 12 |
| September | 65° | 4.0″ | 13 |
| October | 53° | 5.0″ | 17 |
| November | 43° | 4.0″ | 13 |
| December | 34° | 5.1″ | 17 |
Regional context
Boston falls within a warm-summer humid continental climate region. Cities in this zone experience comparable temperature ranges, seasonal patterns, and growing conditions throughout the surrounding area.
Similar climates: Worcester, MA, Springfield, MA, New Bedford, MA, Cambridge, MA, Lowell, MA.
Naturalist notes
Late May brings the emergence of mayapple umbrellas unfurling across woodland floors throughout the Boston area.
Spring peepers begin their evening chorus in March as temperatures climb above freezing consistently.
Frequently asked
- When does it freeze in Boston?
- Boston's final spring frost usually occurs around mid-May, while the first fall frost typically arrives around mid-October.
- What is the rainy season in Boston?
- December records the highest rainfall with approximately 5.1 inches on average; Boston receives roughly 49 inches annually.
- What is the warmest month in Boston?
- July typically registers as the warmest month, averaging about 74°F.
- What is the coldest month in Boston?
- January typically registers as the coldest month, averaging about 28°F.
- When can I start a vegetable garden in Boston?
- Cool-season crops like peas and lettuce can be planted around the last spring frost in mid-May; warm-season crops such as tomatoes and peppers should wait until 1–2 weeks after.
- How many rainy days does Boston get?
- Boston records about 164 rainy days per year on average.
- What hardiness zone is Boston?
- Boston's USDA hardiness zone depends on its lowest average winter temperature; consult the USDA's online lookup using the city ZIP for the current zone designation.
Climate
Boston, Massachusetts experiences a warm-summer humid continental climate zone. Winter temperatures in January typically hover near 28°F, while July averages reach 74°F — creating a 46°F seasonal swing.
Throughout the year, Boston collects about 49 inches of precipitation distributed across roughly 164 rainy days.
Several factors determine the city's seasonal patterns: its latitude at 42.3°N, proximity to large water bodies, and elevation. These elements influence local plant growth, frost timing, and daily weather conditions.