Climate Insights for Charlestown

The climate in Charlestown is temperate. The average annual temperature is 12°C and approximately 1212mm of precipitation falls per year. Charlestown receives a notable amount of rainfall throughout the year, including during its driest month. Charlestown is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, August, September. The coldest months are January, February, December, when temperatures can drop to -2°C. Snowfall occurs from January to December, with around 72cm accumulating over the season.

Temperatures in Charlestown vary considerably across the year, with a 28°C difference between the coldest and warmest months. The warmest month is July, when average highs reach 26°C and the mean temperature sits around 23°C. The coldest month is January, when overnight lows fall to -2°C and the daily average is 1°C. Daily temperature variation is modest, with an average difference of 6°C between highs and lows. The sharpest temperature change occurs between October and November, with a 6°C shift in average temperatures.

Charlestown is a fairly wet location, receiving approximately 1212mm of precipitation annually, which averages out to around 101mm per month. The wettest month is December, averaging 128mm of rainfall. January and October also tend to see above-average precipitation. The driest month is August, with just 82mm. That's 47mm less than December, the wettest month. Rainfall is relatively evenly distributed throughout the year, so there is no pronounced dry or wet season to plan around. Snowfall is a regular feature from January to December, with around 72cm accumulating over the season. February typically sees the most snow at around 22cm.

Charlestown is moderately windy, with an average annual wind speed of 21km/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 24km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in August, with average winds dropping to 18km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 6km/h between the calmest and windiest months. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 24km/h in winter, 22km/h in spring, 18km/h in summer, 21km/h in autumn.

It is currently spring in Charlestown, which began on March 20, 2026. Charlestown 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 January near -2°C. Summer is next, beginning on June 21, 2026 — 92 days from now.

The best time to visit Charlestown is during June, July, August and September, when the weather is most comfortable for travellers. During these months, average temperatures hover around 21°C with modest rainfall averaging 91mm per month. By contrast, January can be quite cold with temperatures dropping to -2°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 Charlestown 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.