Boston, United States experiences average highs of 15°C (59°F) and lows of 7°C (45°F) throughout the year. Rainfall is moderate, averaging about 10 rainy days per month. Average highs have cooled by 1.0°C (1.8°F) across the available records.
Boston, United States Weather & Climate 2026
Monthly climate averages for Boston, United States. Based on 10-year ERA5 reanalysis data.
Climate Overview
Drier season: Jan–Nov 
Wetter season: Mar–Dec At-a-Glance Climate Summary
Live Weather & Air Quality
Key figures
Climate Score
5.4/10
Best: June, July, August, September, October
UV Index
5
Low
Temperature 15°C / 7°C
Feels Like 14°C / 4°C
Rainy Days 10
Rainfall 95 mm
Sunshine 8 h
Humidity 72%
Wind Speed 21 km/h
Dew Point 6°C
Snow Days 5 days
Frost Days 16 days
Hottest Month
28°C
July
Avg Low20°C
Rain10days
Coldest Month
-4°C
January
Avg High3°C
Rain10days
Driest Month
9days
September
Avg High23°C
Avg Low16°C
Windiest Month
24 km/h
March (Gusts 47)
Sea Temperature
3°C – 20°C
Warmest water: August (
20°C
)
Worst Time to Visit
Consider avoiding January, February, March, December due to very cold temperatures, frequent rain.
Sun Position
Sunrise 05:08
Daylight 15.3h
Sunset 20:24
Live conditions—
Boston on the map · live conditions
Boston, United States
- Continent
- Americas
- Country
- United States
- City
- Boston
- Population
- 653.8K
- Elevation
- 14 m
- Coordinates
- 42.36°, -71.06°
Seasonal Breakdown
Spring
Mar–May
Avg High 14°C
Avg Low 5°C
Rain 11 days/mo
Summer
Jun–Aug
Avg High 27°C
Avg Low 18°C
Rain 10 days/mo
3/3 best months
Autumn
Sep–Nov
Avg High 17°C
Avg Low 9°C
Rain 9 days/mo
2/3 best months
Winter
Dec–Feb
Avg High 4°C
Avg Low -4°C
Rain 10 days/mo
Climate Charts
Based on historical averages (2016–2025)
Monthly Temperatures
HighLowShaded bands show the typical range across the available yearly records.
Line chart showing monthly temperatures. Jan: 3°C / -4°C . Feb: 5°C / -4°C . Mar: 8°C / -1°C . Apr: 14°C / 5°C . May: 19°C / 10°C . Jun: 25°C / 16°C . Jul: 28°C / 20°C . Aug: 27°C / 19°C . Sep: 23°C / 16°C . Oct: 17°C / 10°C . Nov: 11°C / 3°C . Dec: 5°C / -2°C .
Monthly Rainfall
Rainfall
Bar chart showing monthly rainfall. Jan: 103 mm. Feb: 90 mm. Mar: 108 mm. Apr: 109 mm. May: 86 mm. Jun: 71 mm. Jul: 94 mm. Aug: 70 mm. Sep: 91 mm. Oct: 113 mm. Nov: 78 mm. Dec: 121 mm.
Monthly Humidity
Humidity
Line chart showing monthly humidity. Jan: 68%. Feb: 70%. Mar: 67%. Apr: 69%. May: 73%. Jun: 73%. Jul: 74%. Aug: 73%. Sep: 76%. Oct: 76%. Nov: 71%. Dec: 72%.
Monthly Wind Speed
Wind SpeedGusts
Bar chart showing monthly wind speed. Jan: 24 km/h . Feb: 23 km/h . Mar: 24 km/h . Apr: 22 km/h . May: 20 km/h . Jun: 18 km/h . Jul: 17 km/h . Aug: 17 km/h . Sep: 18 km/h . Oct: 21 km/h . Nov: 23 km/h . Dec: 23 km/h .
Sunshine
Sunshine
Sunshine: Jan: 6h. Feb: 7h. Mar: 8h. Apr: 9h. May: 10h. Jun: 11h. Jul: 11h. Aug: 11h. Sep: 9h. Oct: 7h. Nov: 7h. Dec: 6h.
Sea Temperature
Sea Temperatureswim
Line chart showing monthly sea temperature. Jan: 4°C . Feb: 3°C . Mar: 5°C . Apr: 8°C . May: 13°C . Jun: 17°C . Jul: 19°C . Aug: 20°C . Sep: 19°C . Oct: 15°C . Nov: 10°C . Dec: 6°C .
UV Index
UV Index
Bar chart showing monthly UV index. Jan: UV 2. Feb: UV 3. Mar: UV 4. Apr: UV 5. May: UV 6. Jun: UV 7. Jul: UV 7. Aug: UV 7. Sep: UV 5. Oct: UV 4. Nov: UV 3. Dec: UV 2.
Monthly Daylight Hours
Daylight12h reference
Monthly Dew Point & Comfort
Dew Point Dry Comfortable Humid Muggy Oppressive
Snow Days
Snow DaysSnowfall
Snow Days: Jan: 8 days. Feb: 8 days. Mar: 4 days. Apr: 2 days. May: 0 days. Jun: 0 days. Jul: 0 days. Aug: 0 days. Sep: 0 days. Oct: 0 days. Nov: 1 days. Dec: 6 days.
Climate Trends
Average highs have cooled by 1.0°C (1.8°F) across the available records. Average rainfall is trending wetter by about 13 mm.
2016 to 2025
Avg high Avg rainfall
Climate summary
| Last 12 months | All years | |
|---|---|---|
| Hottest month | Jul 2025 · 29°C | Jul · 28°C |
| Coldest month | Feb 2025 · -7°C | Jan · -4°C |
| Wettest month | May 2025 · 146 mm | Dec · 121 mm |
| Windiest month | Dec 2025 · 26 km/h | Mar · 24 km/h |
Month-by-Month Weather Table
January
Poor 
February
Poor March
Poor April
Fair May
Good June best
Excellent July best
Excellent August best
Excellent September best
Excellent October best
Good November
Poor December
Poor | Month | Temp | Feels Like | Rain | Sun | Humidity | UV | Status | Details |
|---|---|---|---|---|---|---|---|---|
| January | 3°C / -4°C | -2°C / -10°C | 10days (103 mm) Wet | 5.9h Fair | 68% Muggy | 2.2 Moderate | Poor | View Details |
| February | 5°C / -4°C | 0°C / -9°C | 10days (90 mm) Wet | 6.6h Fair | 70% Muggy | 3.2 Moderate | Poor | View Details |
| March | 8°C / -1°C | 4°C / -6°C | 11days (108 mm) Wet | 7.8h Good | 67% Muggy | 4.3 Moderate | Poor | View Details |
| April | 14°C / 5°C | 11°C / 1°C | 11days (109 mm) Wet | 8.5h Good | 69% Muggy | 5.2 High | Fair | View Details |
| May | 19°C / 10°C | 18°C / 8°C | 11days (86 mm) Wet | 9.7h Good | 73% Muggy | 6.3 High | Good | View Details |
| June best | 25°C / 16°C | 26°C / 15°C | 10days (71 mm) Wet | 11h Excellent | 73% Muggy | 6.7 High | Excellent | View Details |
| July best | 28°C / 20°C | 31°C / 21°C | 10days (94 mm) Wet | 11.1h Excellent | 74% Muggy | 7 High | Excellent | View Details |
| August best | 27°C / 19°C | 29°C / 20°C | 10days (70 mm) Wet | 10.7h Excellent | 73% Muggy | 6.5 High | Excellent | View Details |
| September best | 23°C / 16°C | 23°C / 15°C | 9days (91 mm) Wet | 8.5h Good | 76% Humid | 5.1 High | Excellent | View Details |
| October best | 17°C / 10°C | 16°C / 7°C | 9days (113 mm) Wet | 7h Good | 76% Humid | 3.8 Moderate | Good | View Details |
| November | 11°C / 3°C | 7°C / -1°C | 9days (78 mm) Wet | 6.5h Fair | 71% Muggy | 2.6 Moderate | Poor | View Details |
| December | 5°C / -2°C | 1°C / -7°C | 11days (121 mm) Wet | 5.5h Fair | 72% Muggy | 1.9 Low | Poor | View Details |
Compare Nearby City Climates
Frequently Asked Questions
The best months to visit Boston are June, July, August, September, October, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Boston, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Boston is July, with average daytime highs of 28°C (83°F). Plan outdoor activities for early morning or late afternoon if visiting during this period.
The coldest month in Boston is January, with average overnight lows of -4°C (24°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Boston is December, averaging 121mm of precipitation across 11 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Boston runs through March, April, May, December, with the heaviest rainfall in March. Based on 10-year averages for Boston.
Boston receives approximately 99 sunshine hours per year. The sunniest month is July with around 11 hours. Based on climate data for Boston.
The least favorable months to visit Boston are January, February, March, December, primarily due to very cold temperatures, frequent rain. For the best conditions, consider June, July, August, September, October instead.
The annual average UV index in Boston is 5, classified as moderate. Standard sun protection (sunscreen, hat) is recommended during prolonged outdoor exposure.
Average humidity in Boston is 72%, classified as moderate. Humidity levels are generally comfortable and should not affect outdoor activities for most people.
Sea temperatures in Summer average 12°C (54°F), which most swimmers will find too cold without a wetsuit.
Yes, Boston receives snow. Months with snowfall average 5 snow days and 13 cm (5 in) of accumulation, with about 16 frost days during winter.
Average wind speeds in Boston are 21 km/h (13 mph). The windiest month is March with peak winds reaching 24 km/h (15 mph) (gusts up to 47 km/h / 29 mph).
Boston averages 5 clear-sky days per month with overall cloud cover around 58%. The clearest skies occur in November.
The annual average dew point in Boston is 6°C (43°F), which feels dry and comfortable. Outdoor activities are comfortable year-round from a humidity standpoint.
Boston has a Humid Subtropical climate, classified as Cfa under the Köppen system. Temperate climates have mild winters and warm summers, with rainfall spread across the year and four distinct seasons.
The 'feels like' temperature in Boston ranges from 4°C (39°F) to 14°C (57°F) on average. Wind chill makes winters feel noticeably colder than the actual temperature — layered clothing is recommended.
Yes, June is a great time to visit Boston. It earns a climate score of 8.8/10 with Excellent.
For June in Boston, pack Umbrella, Waterproof jacket, Breathable clothing, Sunscreen (SPF 30+), Sun hat. With average highs of 25°C (77°F) and 10 rainy days, these essentials will keep you comfortable.
Data Source
Climate data derived from ERA5 reanalysis (ECMWF), averaged over 2016–2025. Sea surface temperature from marine reanalysis data. Climate scores and seasonal estimates are computed by WorldStats.
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