Groton Weather in September

Thinking of visiting Groton in September? Expect high temperatures reaching 23°C (73°F) during the day, dropping to 14°C (57°F) at night, and note that quite a bit of rainfall is likely.

Rainfall in Groton in September

Historically, approximately 10 days this month are expected to have rain, averaging 104 mm (4.1 in). When it rains this month, it tends to come down fairly heavily. Showers can be substantial even if they don't last all day.

Temperature in Groton in September

September in Groton sees highs of 23°C (73°F) and lows of 14°C (57°F) overnight. This gives the month a fairly typical daily rhythm, with warmer afternoons and more comfortable nights. Nights drop to around 14°C (57°F), which is noticeably cooler than the daytime. A light jacket for the evening is a sensible addition, and the cool nights tend to make sleeping comfortable.

Sunshine in Groton in September

Enjoy a sunny month with about 223 hours of sunshine, the clear skies make Groton even more beautiful.

Should you favor a climate that's both dry and comfortably warm, July and August typically offer the most agreeable circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.

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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 Groton's climate page.

Groton Temperature in September

Min Temperature 14°C (57°F)  

Max Temperature 23°C (73°F)  

Chance of Rain 32%  

Precipitation 104 mm (4.1 in)  

Rainy days 10 days  

Humidity 72% *  

Sunshine 223 hours *  

Percentage Sunshine 60% *  

* Data from: Hartford, the United States of America (68 KM, 42 Miles).

What to Wear in Groton in September

For Groton in September, you'll want flexible clothing. It's wise to pack cotton shirts, comfortable shorts, and a pair of jeans for cooler evenings. A light sweater or jacket is useful for air-conditioned spaces (like buses) or unexpected cool moments. High rain levels are expected, so pack waterproof gear and an umbrella or poncho. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.

What To Do in Groton 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

Camping

6/10

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 Groton's climate page.

More climate data for Groton

Temperature Rainfall Sunshine Humidity

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