Stamford

Connecticut Weather in September

Average temperatures, rainfall, sunshine and the best places to visit in Connecticut, the United States of America in September.

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Mystic Danbury Windsor Locks Groton

Planning a getaway to Connecticut, the United States of America this September and curious about the weather you should prepare for? Discover all the vital details you need on this page, solving your puzzle:

What to Expect in Connecticut in September

Connecticut, the United States of America is a region in the United States of America. September in Connecticut generally has warm temperatures, with precipitation levels ranging from moderate to high. The month of September is in the summer season.

Temperatures

The average maximum temperatures are warm and range from 23°C (73°F) in Cornwall Bridge to 25°C (77°F) in East Hartford. Nighttime temperatures generally drop to 14°C (57°F) in East Hartford and 11°C (52°F) in Cornwall Bridge.

For specific regional insights in Connecticut, the United States of America, refer to the map provided below.

Precipitation

In September, precipitation varies across different areas. From moderate rainfall in Manchester with an average of 81 mm (3.2 in) to high rainfall in Old Saybrook with 115 mm (4.5 in).

Average sunshine

September brings good sunshine to many areas. Mystic sees around 233 hours of sunlight, great for visitors looking for bright days.

Explore Connecticut by month

Pick a month to see the average temperature, rainfall and sunshine in Connecticut — and find the best time to visit. (based on Mystic)

January4°C (39°F) February4°C (39°F) March8°C (46°F) April14°C (57°F) May19°C (66°F) June23°C (73°F) This monthJuly27°C (81°F) August26°C (79°F) September23°C (73°F) October18°C (64°F) November12°C (54°F) December7°C (45°F)
Best Time to Visit Connecticut →

Best Places to Visit in Connecticut in September

Click on a destination dot for more details. Toggle the map to compare temperatures or precipitation across Connecticut.

Conditions Temperatures Precipitation
perfect weather
pleasant
tolerable
unpleasant
poor

Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C (68°F) and 29°C (84°F) and not too much precipitation (less than 90 mm (3.5 in) a month).

Popular Destinations in Connecticut

What is the weather like in September for some of the most popular destinations in Connecticut, the United States of America?

Temperature range in Connecticut (September)

Precipitation variation in Connecticut (September)

Mystic

In September Mystic generally has high temperatures with maximum daytime temperatures around 23°C (73°F), minimum nighttime temperatures around 14°C (57°F) and moderate monthly rainfall. So on average the conditions are perfect that month.

« August
September
October »
August
September
October
Max temperature
26°C (79°F)
23°C (73°F)
18°C (64°F)
Min temperature
18°C (64°F)
14°C (57°F)
8°C (46°F)
Monthly sun hours
260 hours
233 hours
208 hours
Monthly rainfall
89 mm (3.5 in)
98 mm (3.9 in)
108 mm (4.3 in)
Monthly rainy days
9 days
9 days
13 days
Weather conditions
perfect
perfect
tolerable
Climate in Mystic →

Danbury

In September Danbury generally has high temperatures with maximum daytime temperatures around 24°C (75°F), minimum nighttime temperatures around 12°C (54°F) and high monthly rainfall. So on average the conditions are pleasant that month.

« August
September
October »
August
September
October
Max temperature
27°C (81°F)
24°C (75°F)
17°C (63°F)
Min temperature
16°C (61°F)
12°C (54°F)
6°C (43°F)
Monthly rainfall
133 mm (5.2 in)
101 mm (4 in)
124 mm (4.9 in)
Monthly rainy days
12 days
10 days
13 days
Weather conditions
pleasant
pleasant
unpleasant
Climate in Danbury →

Windsor Locks

In September Windsor Locks generally has high temperatures with maximum daytime temperatures around 25°C (77°F), minimum nighttime temperatures around 13°C (55°F) and high monthly rainfall. So on average the conditions are pleasant that month.

« August
September
October »
August
September
October
Max temperature
29°C (84°F)
25°C (77°F)
18°C (64°F)
Min temperature
17°C (63°F)
13°C (55°F)
7°C (45°F)
Monthly sun hours
269 hours
223 hours
199 hours
Monthly rainfall
127 mm (5 in)
103 mm (4.1 in)
124 mm (4.9 in)
Monthly rainy days
11 days
9 days
12 days
Weather conditions
pleasant
pleasant
tolerable
Climate in Windsor Locks →

Groton

In September Groton generally has high temperatures with maximum daytime temperatures around 23°C (73°F), minimum nighttime temperatures around 14°C (57°F) and high monthly rainfall. So on average the conditions are pleasant that month.

« August
September
October »
August
September
October
Max temperature
26°C (79°F)
23°C (73°F)
18°C (64°F)
Min temperature
18°C (64°F)
14°C (57°F)
8°C (46°F)
Monthly sun hours
269 hours
223 hours
199 hours
Monthly rainfall
96 mm (3.8 in)
104 mm (4.1 in)
107 mm (4.2 in)
Monthly rainy days
10 days
10 days
13 days
Weather conditions
perfect
pleasant
tolerable
Climate in Groton →

Milford

In September Milford generally has high temperatures with maximum daytime temperatures around 25°C (77°F), minimum nighttime temperatures around 15°C (59°F) and moderate monthly rainfall. So on average the conditions are perfect that month.

« August
September
October »
August
September
October
Max temperature
28°C (82°F)
25°C (77°F)
18°C (64°F)
Min temperature
19°C (66°F)
15°C (59°F)
9°C (48°F)
Monthly sun hours
269 hours
223 hours
199 hours
Monthly rainfall
116 mm (4.6 in)
92 mm (3.6 in)
101 mm (4 in)
Monthly rainy days
11 days
10 days
12 days
Weather conditions
pleasant
perfect
tolerable
Climate in Milford →

Is your destination not in the list? Have a look at all destinations in Connecticut, in the United States of America.

Popular cities in September

Day & night temperatures, rainfall and average weather in Connecticut in September.

City Weather Day temp Night temp Rainfall
Mystic 23°C (73°F) 14°C (57°F) 98 mm (3.9 in)
Danbury 24°C (75°F) 12°C (54°F) 101 mm (4 in)
Windsor Locks 25°C (77°F) 13°C (55°F) 103 mm (4.1 in)
Groton 23°C (73°F) 14°C (57°F) 104 mm (4.1 in)
Milford 25°C (77°F) 15°C (59°F) 92 mm (3.6 in)
Norwalk 25°C (77°F) 14°C (57°F) 94 mm (3.7 in)

Connecticut weather in September: frequently asked questions

What is the weather like in Connecticut, the United States of America in September?

Expect perfect weather across Connecticut, the United States of America in September. The popular destination of Mystic averages 23°C (73°F) by day and 14°C (57°F) at night during this summer month.

What is the average temperature in Connecticut, the United States of America in September?

Daytime temperatures in Mystic peak at roughly 23°C (73°F) in September, dropping to about 14°C (57°F) overnight.

Does Connecticut, the United States of America get a lot of rain in September?

Not particularly. Mystic averages just 98 mm (3.9 in) of rain in September, making it a mostly dry month for Connecticut, the United States of America.

Is September a Good Time to Visit Connecticut, the United States of America?

We believe that September is one of the best times to visit Connecticut, the United States of America with overall perfect weather in Mystic. It's worth noting that weather conditions might differ depending on the location you visit.

On average, the best time to visit Connecticut, the United States of America is in August and September with generally perfect weather in Mystic. In contrast, January, February, March and December tend to have poor weather conditions.

Interested in more climate information?

We have much more information about the climate in Connecticut.

Weather and climate has detailed information for every country in the world. Are you going to the United States of America? Get detailed historical weather averages for many cities in the United States of America.

Not sure yet where to go? We now have a tool which recommends destinations that suit your ideal travel conditions. Find out where to go with our weather planner.

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