Climate Insights for Casper

The climate in Casper is cool. The average annual temperature is 7°C and approximately 408mm of precipitation falls per year. May is the wettest month, receiving around 65mm of rainfall. Casper is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, August, June. The coldest months are January, February, December, when temperatures can drop to -11°C. Casper experiences heavy snowfall, typically from January through December.

Casper has a wide annual temperature range, spanning 42°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 January, when overnight lows fall to -11°C and the daily average is -7°C. On average, daily temperatures fluctuate by about 13°C between overnight lows and afternoon highs. The sharpest temperature change occurs between September and October, with a 9°C shift in average temperatures.

Casper is a relatively dry area, receiving approximately 408mm of precipitation annually, which averages out to around 34mm per month. The wettest month is May, averaging 65mm of rainfall. April and March also tend to see above-average precipitation. The driest month is July, with just 12mm. That's 53mm less than May, 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 204cm annually from January through December. The snowiest month is April, with approximately 39cm. Winter travel should account for significant snow cover.

Casper is mildly breezy, with an average annual wind speed of 13km/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 15km/h, though still comfortable for most outdoor activities. The calmest conditions occur in August, with average winds dropping to 11km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 4km/h gap 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 15km/h in winter, 13km/h in spring, 11km/h in summer, 13km/h in autumn.

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 January near -11°C. Autumn is next, beginning on September 23, 2026 (7 days from now).

The best time to visit Casper is during June, July, August and September, when the weather is most comfortable for travellers. During these months, average temperatures hover around 19°C with modest rainfall averaging 23mm per month. By contrast, January can be quite cold with temperatures dropping to -11°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.