Williamstown Weather in September

Thinking of visiting Williamstown in September? Expect high temperatures reaching 26°C (79°F) during the day, dropping to 15°C (59°F) at night, and note that quite a bit of rainfall is likely.

Rainfall in Williamstown in September

Based on our climate data of the past 30 years, about 8 days of rain are anticipated, with 108 mm (4.3 in) on average. Individual showers can be quite heavy this month. A proper umbrella or rain jacket is worth having.

Temperature in Williamstown in September

Daytime temperatures in Williamstown reach 26°C (79°F) in September, dropping to 15°C (59°F) at night. This kind of day-to-night contrast is typical for this time of year. At 15°C (59°F) overnight, it can feel quite a bit cooler after dark. Worth packing something warmer for evenings, but the cooler temperatures are ideal for sleeping.

Sunshine in Williamstown in September

Expect sunny days throughout the month, with an estimated 218 hours of sunshine. This makes it a pleasant time to visit Williamstown.

Our weather planner can help you find worldwide destinations with pleasant weather during this period. May typically offers the best weather for Williamstown.

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

Williamstown Temperature in September

Min Temperature 15°C (59°F)  

Max Temperature 26°C (79°F)  

Chance of Rain 27%  

Precipitation 108 mm (4.3 in)  

Rainy days 8 days  

Humidity 72% *  

Sunshine 218 hours *  

Percentage Sunshine 59% *  

* Data from: Philadelphia, the United States of America (32 KM, 20 Miles).

What to Wear in Williamstown in September

Warm temperatures in September make for comfortable sightseeing weather. Pack breathable fabrics like cotton shirts, knee-length shorts or skirts, and comfortable walking shoes. A thin long sleeve for indoor spaces is handy. Prepare for significant rainfall with proper waterproof clothing and shoes. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.

What To Do in Williamstown in September

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

Swimming

9/10

Cycling

7/10

Walking

7/10

Camping

6/10

Outdoor sports

7/10

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 Williamstown's climate page.

More climate data for Williamstown

Temperature Rainfall Sunshine Humidity

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