Old Lyme (CT) Weather & Climate: Best Time to Visit

Visitors to Old Lyme can expect significant temperature changes throughout the year. Average daytime temperatures reach a comfortable 28°C (82°F) in July. In January, the coolest month of the year, temperatures drop to a chilly 4°C (39°F).

At night, temperatures range from around 19°C (66°F) in July to -5°C (23°F) in January.

Check out our detailed temperature page for more information.

Temperature ranges by month

Old Lyme is known for its substantial rain/snowfall, with annual precipitation reaching 1289 mm (51 in). Despite minor fluctuations, Old Lyme enjoys fairly consistent precipitation throughout the year. In June, you can expect around 135 mm (5.3 in) of precipitation, while in November, Old Lyme receives about 92 mm (3.6 in). For more details, please visit our Old Lyme Precipitation page.

The mean monthly precipitation over the year, including rain, hail, and snow

The average number of days each month with precipitation

Old Lyme can be enjoyed more throughout the sunniest month of July under a blue sky, with approximately 9.8 hours of sunshine daily. In contrast, the city experiences much darker days in November, with only 4.6 hours of sunlight per day.

Visit our detailed sunshine hours page for more information.

Monthly hours of sunshine

Daily hours of sunshine

Daily percentage of sunshine

The relative humidity is high throughout the year in Old Lyme.

The city experiences its highest humidity in September, reaching 72%. In April, the humidity drops to its lowest level at 58%. What does this mean? Read our detailed page on humidity levels for further details.

Relative humidity over the year