Chelsea Weather in September

September in Chelsea brings high temperatures, with highs of 24°C (75°F) and nights dropping to 15°C (59°F). It's also the driest month of the year, ideal for those who want to avoid rain.

Rainfall in Chelsea in September

With the least rainfall of the year, this month offers good conditions for outdoor exploration. Take advantage of the dry weather to plan your activities. You can typically expect 9 days of rain this month, averaging around 79 mm (3.1 in). When showers do arrive, they tend to be on the heavier side. Worth being prepared even if rain days are not that numerous.

Temperature in Chelsea in September

Weather in Chelsea is at its excellent in September. Highs reach 24°C (75°F), while nights settle around 15°C (59°F). The days can feel warmer than the evenings, so packing for both parts of the day is a good idea. Nights cool down to 15°C (59°F), so a light jacket or extra layer is useful once the sun goes down. On the plus side, the cooler nights make for comfortable sleeping conditions.

Sunshine in Chelsea in September

Expect a lot of sunshine this month, with about 238 hours of sun. These sunny conditions add to the overall experience.

Wind Speed in Chelsea in September

September has wind speeds averaging 5 m/s (10 knots). You can expect gentle to moderate winds that move small trees and make flags wave steadily on typical days. Conditions typically range from light breezes to moderate winds.

Average water temperature in September

With water at 18°C (64°F), swimming is comfortable for most people. It feels refreshing rather than cold, though it depends a bit on personal preference.

If you're inclined towards comfortable temperatures and drier conditions, September is a good time to visit Chelsea.

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Check the conditions for any month of the year.

• January
• February
• March
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• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Chelsea's climate page.

Chelsea Temperature in September

Min Temperature 15°C (59°F)  

Max Temperature 24°C (75°F)  

Water Temperature 18°C (64°F) *  

Chance of Rain 30%  

Precipitation 79 mm (3.1 in)  

Rainy days 9 days  

Humidity 69% *  

Windspeed 5 m/s (10 knots) *  

Sunshine 238 hours *  

Percentage Sunshine 63% *  

* Data from: Boston, the United States of America (2 KM, 1 Miles).

What to Wear in Chelsea in September

Pleasant temperatures in September mean you can pack light but flexibel pieces. Think cotton t-shirts, comfortable walking shorts, and one warmer layer for evenings. A light sweater or denim jacket works well. Rain gear is recommended, you can expect wet weather on multiple days. The water temperature sits at about 18°C (64°F), which is too chilly for most people to enjoy swimming. Leave the swimsuit at home unless you love cold water. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.

What To Do in Chelsea in September

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

9/10

Cycling

9/10

Walking

9/10

Barbeque

8/10

Camping

8/10

Outdoor sports

9/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Chelsea's climate page.

More climate data for Chelsea

Temperature Rainfall Sunshine Humidity Wind Speed Water Temp

See the full Chelsea climate overview or explore weather in the United States of America.