Climate Insights for Dartmouth

The climate in Dartmouth is cool. The average annual temperature is 8°C and approximately 1284mm of precipitation falls per year. Dartmouth receives a notable amount of rainfall throughout the year, including during its driest month. Dartmouth is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: August, July, September. The coldest months are January, February, December, when temperatures can drop to -7°C. Dartmouth experiences heavy snowfall, typically from January through December.

Temperatures in Dartmouth vary considerably across the year, with a 31°C difference between the coldest and warmest months. August is the warmest month, though highs remain moderate at 24°C with a mean of 19°C. The coldest month is January, when overnight lows fall to -7°C and the daily average is -3°C. Daily temperature variation is modest, with an average difference of 8°C between highs and lows. The sharpest temperature change occurs between November and December, with a 6°C shift in average temperatures.

Dartmouth is a fairly wet location, receiving approximately 1284mm of precipitation annually, which averages out to around 107mm per month. The wettest month is October, averaging 131mm of rainfall. November and April also tend to see above-average precipitation. The driest month is August, with just 73mm. That's 58mm less than October, the wettest month. Rainfall is relatively evenly distributed throughout the year, so there is no pronounced dry or wet season to plan around. Dartmouth receives heavy snowfall, accumulating around 236cm annually from January through December. The snowiest month is January, with approximately 57cm. Winter travel should account for significant snow cover.

Dartmouth is relatively calm, with an average annual wind speed of 4km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is March, averaging 5km/h, though still comfortable for most outdoor activities. The calmest conditions occur in July, with average winds dropping to 3km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 2km/h gap between the calmest and windiest months.

It is currently summer in Dartmouth, which began on June 21, 2026. Dartmouth 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 August at around 24°C, while the coldest stretch bottoms out in January near -7°C. Autumn is next, beginning on September 23, 2026 — 93 days from now.

The best time to visit Dartmouth is during July, August and September, when the weather is most comfortable for travellers. During these months, average temperatures hover around 18°C with modest rainfall averaging 79mm per month. By contrast, January can be quite cold with temperatures dropping to -7°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 Dartmouth 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.