Climate Insights for Casper

The climate in Casper is cool. The average annual temperature is 7°C and approximately 419mm of precipitation falls per year. April is the wettest month, receiving around 100mm of rainfall. Casper is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, June, August. The coldest months are December, January, February, when temperatures can drop to -13°C. Casper experiences heavy snowfall, typically from January through December.

Casper has a wide annual temperature range, spanning 44°C from the coldest to warmest months. The warmest month is July, when average highs reach 31°C and the mean temperature sits around 22°C. The coldest month is December, when overnight lows fall to -13°C and the daily average is -8°C. On average, daily temperatures fluctuate by about 13°C between overnight lows and afternoon highs. The sharpest temperature change occurs between November and December, with a 13°C shift in average temperatures.

Casper is a relatively dry area, receiving approximately 419mm of precipitation annually, which averages out to around 35mm per month. The wettest month is April, averaging 100mm of rainfall. March and May also tend to see above-average precipitation. The driest month is July, with just 7mm. That's 93mm less than April, 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. Casper receives heavy snowfall, accumulating around 253cm annually from January through December. The snowiest month is April, with approximately 73cm. Winter travel should account for significant snow cover.

Casper 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 December, averaging 5km/h, though still comfortable for most outdoor activities. The calmest conditions occur in August, 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 Casper, which began on June 21, 2026. Casper 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 31°C, while the coldest stretch bottoms out in December near -13°C. Autumn is next, beginning on September 23, 2026 — 52 days from now.

The best time to visit Casper is during June, July and August, when the weather is most comfortable for travellers. During these months, average temperatures hover around 21°C with modest rainfall averaging 12mm per month. By contrast, December can be quite cold with temperatures dropping to -13°C. With minimal rainfall expected, you can pack light and plan outdoor activities with confidence.

The table below shows monthly climate averages for Casper 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.