Climate Insights for Chatham

The climate in Chatham is temperate. The average annual temperature is 14°C and approximately 932mm of precipitation falls per year. July is the wettest month, receiving around 142mm of rainfall. Chatham is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: June, July, August. The coldest months are January, December, February, when temperatures can drop to -5°C. Light snow can occur between January and December.

Chatham has a wide annual temperature range, spanning 36°C from the coldest to warmest months. The warmest month is June, when average highs reach 31°C and the mean temperature sits around 25°C. The coldest month is January, when overnight lows fall to -5°C and the daily average is -1°C. On average, daily temperatures fluctuate by about 10°C between overnight lows and afternoon highs. The sharpest temperature change occurs between November and December, with a 10°C shift in average temperatures.

Chatham is a moderately rainy area, receiving approximately 932mm of precipitation annually, which averages out to around 78mm per month. The wettest month is July, averaging 142mm of rainfall. August and September also tend to see above-average precipitation. The driest month is January, with just 30mm. That's 112mm less than July, the wettest month. Precipitation varies noticeably between seasons, with the second half (July to December) of the year generally seeing more rainfall. Light snowfall can occur between January and December, totalling around 47cm annually. February is the snowiest month with approximately 19cm.

Chatham 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 February, averaging 4km/h, though still comfortable for most outdoor activities. The calmest conditions occur in August, with average winds dropping to 2km/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 Chatham, which began on June 21, 2026. Chatham 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 June at around 31°C, while the coldest stretch bottoms out in January near -5°C. Autumn is next, beginning on September 23, 2026 — 52 days from now.

The best time to visit Chatham is during May and October, when the weather is most comfortable for travellers. During these months, average temperatures hover around 17°C with modest rainfall averaging 70mm per month. By contrast, June can be uncomfortably hot with highs reaching 31°C, while January is the coldest period with lows dropping to -5°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 Chatham 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.