Chelsea (MA) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Chelsea.
Climate overview of Chelsea
Chelsea, Massachusetts, United States of America, sees big temperature differences between seasons, with July peaking at 29°C (84°F) and January dropping to 3°C (37°F).
Rain/snowfall is high, totalling around 1232 mm (49 in) per year. December is the wettest month and September the driest. The city also experiences warm summers and cold winters. The most sunshine falls in May, with an average of 10.0 hours of daily sunshine.
Chelsea Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Chelsea - and find the best time to visit.
Monthly Temperature in Chelsea
Visitors to Chelsea can expect significant temperature changes throughout the year. Average maximum daytime temperatures range from a comfortable 29°C (84°F) in July, the warmest time of the year, to a chilly 3°C (37°F) during cooler months like January.
At night, you can expect temperatures ranging from 19°C (66°F) in July to around -6°C (21°F) during January.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Chelsea
Chelsea is known for its substantial rain/snowfall, with annual precipitation reaching 1232 mm (49 in). While snow/rainfall varies throughout the year, each season offers its own charm. December brings wetter days averaging 132 mm (5.2 in) of precipitation, spread over 12 snowy/rainy days.
In contrast, the driest month September experiences a drier climate, with about 79 mm (3.1 in) of rainfall spread across 9 rainy days. For more details, please visit our Chelsea Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in Chelsea
Seasonal changes in sunshine hours are quite dramatic in Chelsea. While May receives considerable daily sunshine with up to 10.0 hours, December marks the darkest time of the year, where sunshine is scarce with only 4.7 hours of sunlight per day.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Water Temperature in Chelsea
The mean water temperature over the year ranges from 4°C (39°F) in February to 20°C (68°F) in August.
Water temperature over the year
Humidity in Chelsea by Month
The relative humidity is high throughout the year in Chelsea.
The city experiences its highest humidity in August, reaching 72%. In February, the humidity drops to its lowest level at 62%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Wind Speed in Chelsea
The mean wind speed varies between 5 m/s (10 knots) and 7 m/s (14 knots) throughout the year. It is lowest in June, July, August and September and highest during January, February, March and December. What does this mean?
The mean monthly wind speed over the year (meters per second)
Best Time to Visit Chelsea
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: August and September
- Warmest weather: July and August
- Most sunshine: May and July
- Best for swimming: August, with water temperatures around 20°C (68°F).
- Seasonal pattern: Warm summers and cold winters
- Coldest conditions: January, with freezing nights around -6°C (21°F).
Frequently asked questions about the climate in Chelsea
What is the best time to visit Chelsea?
August and September typically offer the most optimal weather in Chelsea. In contrast, January, February, March and December tend to have less optimal conditions. Chelsea has warm summers and cold winters.
What temperatures can I expect in Chelsea?
Daytime highs range from 3°C (37°F) in January to 29°C (84°F) in July. Nighttime lows range from -6°C (21°F) to 19°C (66°F). Temperatures vary considerably through the year.
How much rain does Chelsea get?
Annual rainfall is around 1232 mm (49 in). December is the wettest month with 132 mm (5.2 in), while September is the driest with 79 mm (3.1 in). In the coldest months, precipitation may fall as snow/rain.
How sunny is Chelsea?
Chelsea receives around 2,665 hours of sunshine per year. May is the sunniest month with 301 hours, while December is the cloudiest with just 141 hours. Overall, Chelsea enjoys abundant sunshine.
Chelsea 3-Day Forecast
Chelsea on the map
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