Climate Insights for Cohasset

The climate in Cohasset is cool. The average annual temperature is 5°C and approximately 721mm of precipitation falls per year. September is the wettest month, receiving around 90mm of rainfall. Cohasset is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, August, June. The coldest months are February, January, December, when temperatures can drop to -15°C. Snowfall occurs from January to December, with around 108cm accumulating over the season.

Cohasset has a wide annual temperature range, spanning 41°C from the coldest to warmest months. The warmest month is July, when average highs reach 26°C and the mean temperature sits around 21°C. The coldest month is February, when overnight lows fall to -15°C and the daily average is -11°C. On average, daily temperatures fluctuate by about 9°C between overnight lows and afternoon highs. The sharpest temperature change occurs between April and May, with a 9°C shift in average temperatures.

Cohasset is a relatively dry area, receiving approximately 721mm of precipitation annually, which averages out to around 60mm per month. The wettest month is September, averaging 90mm of rainfall. June and July also tend to see above-average precipitation. The driest month is January, with just 19mm. That's 71mm less than September, the wettest month. Precipitation varies noticeably between seasons, with the second half (July to December) of the year generally seeing more rainfall. Snowfall is a regular feature from January to December, with around 108cm accumulating over the season. December typically sees the most snow at around 27cm.

Cohasset is mildly breezy, with an average annual wind speed of 19km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is October, averaging 21km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in July, with average winds dropping to 17km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 4km/h between the calmest and windiest months.

It is currently spring in Cohasset, which began on March 20, 2026. Cohasset is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in July at around 26°C, while the coldest stretch bottoms out in February near -15°C. Summer is next, beginning on June 21, 2026 — 89 days from now.

The best time to visit Cohasset is during June, July, August and September, when the weather is most comfortable for travellers. During these months, average temperatures hover around 19°C with modest rainfall averaging 88mm per month. By contrast, February can be quite cold with temperatures dropping to -15°C. Despite being the best months overall, some rain is still likely — pack a waterproof layer and plan a mix of indoor and outdoor activities.

The table below shows monthly climate averages for Cohasset based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.