Helena (MT) Weather & Climate: Best Time to Visit

The climate in Helena is known for significant temperature differences throughout the year, making the weather dynamic. Typically, average maximum daytime temperatures range from a comfortable 29°C (84°F) in July to a very cold 0°C (32°F) in the coolest month, December.

Nights vary from 12°C (54°F) in July to around -10°C (14°F) during the colder months.

Check out our detailed temperature page for more information.

Temperature ranges by month

Helena has a relatively dry climate with low precipitation, averaging 373 mm (15 in) of rain/snowfall annually. The climate in Helena shows significant variation throughout the year. Expect moderate rainfall in May, the wettest month, with an average of 59 mm (2.3 in) of precipitation over 15 rainy days.

In contrast, the driest month January offers drier and sunnier days, with around 17 mm (0.7 in) of snowfall over 11 snowy days. For more details, please visit our Helena Precipitation page.

The mean monthly precipitation over the year, including rain, hail, and snow

The average number of days each month with precipitation

For those who appreciate different seasons, Helena serves as an ideal destination. Expect longer, more sun-filled days in July with an average of 12.3 hours of sunshine daily, and embrace the darker days in December, offering only 3.3 hours of daily sunlight.

Visit our detailed sunshine hours page for more information.

Monthly hours of sunshine

Daily hours of sunshine

Daily percentage of sunshine

The relative humidity is moderate throughout the year in Helena.

The city experiences its highest humidity in December, reaching 68%. In July, the humidity drops to its lowest level at 46%. What does this mean? Read our detailed page on humidity levels for further details.

Relative humidity over the year