Climate Insights for Mount Washington

The climate in Mount Washington is temperate. The average annual temperature is 15°C and approximately 1217mm of precipitation falls per year. July is the wettest month, receiving around 213mm of rainfall. Mount Washington is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: August, July, June. The coldest months are January, December, February, when temperatures can drop to -3°C. Light snow can occur between January and February.

Temperatures in Mount Washington vary considerably across the year, with a 33°C difference between the coldest and warmest months. The warmest month is August, when average highs reach 30°C and the mean temperature sits around 26°C. The coldest month is January, when overnight lows fall to -3°C and the daily average is 0°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 7°C shift in average temperatures.

Mount Washington is a fairly wet location, receiving approximately 1217mm of precipitation annually, which averages out to around 101mm per month. The wettest month is July, averaging 213mm of rainfall. May and March also tend to see above-average precipitation. The driest month is October, with just 24mm. That's 189mm less than July, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic. Light snowfall can occur between January and February, totalling around 41cm annually. January is the snowiest month with approximately 27cm.

Mount Washington is relatively calm, with an average annual wind speed of 3km/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 3km/h, though still comfortable for most outdoor activities. The calmest conditions occur in July, 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 1km/h gap between the calmest and windiest months.

It is currently summer in Mount Washington, which began on June 21, 2026. Mount Washington 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 30°C, while the coldest stretch bottoms out in January near -3°C. Autumn is next, beginning on September 23, 2026 — 52 days from now.

The best time to visit Mount Washington is during June, September and October, when the weather is most comfortable for travellers. During these months, average temperatures hover around 21°C with modest rainfall averaging 50mm per month. By contrast, August can be uncomfortably hot with highs reaching 30°C, while January is the coldest period with lows dropping to -3°C. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.

The table below shows monthly climate averages for Mount Washington 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.