Old Greenwich, CT Weather - Forecast & Monthly Averages

Get 300+ Local Insights for Any Address in Old Greenwich, CT

Get Access to 300+ Local Data Points

TEMPERATURE	48
HUMIDITY	66
PRESSURE	102065.75
WIND COND.	360 9.3

Weather Quick Facts

The highest monthly average temperature in Old Greenwich for July is 74.5 degrees
The lowest monthly average temperature in Old Greenwich for January is 30.4 degrees
The most monthly precipitation in Old Greenwich occurs in June with 5.1 inches
The air quality index in Old Greenwich is 2% worse than the national average
The pollution index in Old Greenwich is 522% worse than the national average

Compare Old Greenwich, CT Weather

Compare Neighborhoods & Addresses

Why stop at city-to-city? With Local Insights, you can compare neighborhoods, zip codes, or even exact addresses. Access 300+ hyperlocal data points—from schools and crime to housing and amenities—to see which area is the better fit.

UNLOCK FULL COMPARISON →

Write a review to give others more information about this area.

See all Old Greenwich poll results

Old Greenwich Average Temperature

In the event that the weather data was unavailable for this city, estimates based upon nearby cities were used.
Month	Temp. _(min)	Temp. _(max)	Temp. _(avg)	Precipitation
January	23°F	39°F	30°F	3.0"
February	23°F	40°F	31°F	2.6"
March	30°F	49°F	39°F	3.5"
April	41°F	62°F	50°F	4.2"
May	50°F	71°F	60°F	4.2"
June	60°F	79°F	69°F	5.1"
July	66°F	84°F	74°F	4.4"
August	64°F	82°F	72°F	4.2"
September	57°F	77°F	66°F	4.3"
October	47°F	65°F	55°F	5.1"
November	37°F	54°F	45°F	3.1"
December	29°F	44°F	36°F	4.5"

The best places in Connecticut

Here are the best places to live in Connecticut

These are the 10 cheapest cities in Connecticut

Most Dangerous Cities In The US

Safest States In The US

Old Greenwich air quality index & pollution index

In the event that the air quality/pollution data was unavailable for this city, estimates based upon nearby cities were used.
Index	Old Greenwich	Connecticut	National
Air quality index	43	43	42
Pollution index	16,950,700	8,629,883	2,726,193

Old Greenwich air quality

Measurement	Total
Days measured	365
Days with good air quality	262
Days with moderate air quality	82
Days w/ poor A.Q. for sensitive groups	18
Days with unhealthy air quality	3

Air quality details

Pollutant	Total
Arsenic	0.030%
Benzene	0.140%
Carbon Tetrachloride	0.070%
Lead	0.080%
Mercury	0.030%

Average monthly Old Greenwich temperature with heat index

Old Greenwich monthly precipitation with daily maximum

Old Greenwich monthly snow depth with daily maximum

Old Greenwich monthly wind speed information

Nearby cities with good air quality

City	Population	Air Quality Index	National Avg.
Pemberwick, CT	3,487	43	14.0%
Rye Brook, NY	9,554	43	14.0%
Darien, CT	21,519	43	14.0%
Southport, CT	1,710	43	14.0%
Armonk, NY	4,440	43	14.0%
Old Greenwich, CT	6,980	43	14.0%

Cities with similar population

City	Population	Air Quality Index	National Avg.
King, NC	6,980	45	10.0%
Great Neck Plaza, NY	6,980	51	2.0%
Oak Ridge, NC	6,979	43	14.0%
Clinton, IL	6,982	44	12.0%
Benton, IL	6,977	43	14.0%
Old Greenwich, CT	6,980	43	14.0%

Source: The Old Greenwich, CT weather data displayed above is derived from the NOAA (National Oceanic and Atmospheric). Air quality and pollution data is derived from the EPA (United States Environmental Protection Agency). Air quality and pollution levels measured in a particular area may not be representative of the entire county.