Avg High
Boston in September
Verdict
In Boston, September has a distinct autumn feel. As the season moves along, temperatures are dropping quickly. You can usually expect a mild month that feels variable day to day. Breezes can be part of the character, especially in exposed spots.
It suits travellers who want straightforward weather for sightseeing and day trips. Lookouts and coastal walks can feel sharper when the wind is up.
Avg Low
Rain
Daylight
12h
What to expect
- Daytime feel - Summer-like warmth with evenings that feel distinctly cooler. Overall it feels close to what you’d expect.
- Rain pattern - Often wet. Waterproof footwear becomes genuinely useful. A rain layer is a smart default.
- Sun exposure - Sun protection matters. Cloud cover doesn't always mean low UV, so still protect your skin. Even short walks can add up.
- Breezes - A steady breeze, and expect sharp gusts that can change plans in exposed areas. Sheltered streets can feel fine, but open areas feel very different.
September in context
How it compares to the rest of the year in Boston.
Hottest (avg)
#4 / 12
Wettest (avg)
#6 / 12
Daylight Hours
#6 / 12
Windiest (avg)
#9 / 12
Highest UV
#6 / 12
Most Humid
#1 / 12
Temperature
- Daytime high
-
- Nighttime low
-
- Feels like (avg)
-
Sunshine
- Daylight
- 12.5 hours
- UV index (max)
- 7
- Typical sun hours
- 05:24 – 17:53
Rain & Snow
- Total
-
- Rainy days
- 10
- Cloud cover
- 52%
- Snowfall
-
Humidity & Wind
- Humidity (avg)
- 75%
- Wind (avg)
-
- Wind (max gusts)
-
Frequently asked questions
Is September a good time to visit Boston?
Typical September days in Boston reach highs of 23°C (73°F) with nights around 14°C (57°F). It usually feels warm by day and cool after dark. Overall, September sits in the middle of the Boston climate range.
What are temperatures like in September?
In September, you can usually expect highs of 23°C (73°F) and lows near 14°C (57°F). That means warm days and cool nights, so pack layers you can add or remove.
How much does it rain in September?
Rainfall in September averages 95 mm (3.7 in) across roughly 10 days. Overall it is a quite rainy time of year, so a light rain jacket and waterproof shoes are very handy.
How many hours of daylight are there in September?
You can expect about 12 hours of daylight in September. Sunrise is typically around 05:24 and sunset near 17:53. Daylight is fairly typical, with enough time for sightseeing.
How strong is the sun in September?
UV levels are often high (around 7). Regular sunscreen and a hat are recommended.
Is it windy in September?
In September, average wind speeds are around 13 km/h (8 mph), with gusts on the windiest days reaching about 50 km/h (31 mph). On the ground, it is it can feel quite windy at times, particularly when weather systems move through.