Glacier National Park Weather in May

The climate in Glacier National Park during May can be summarized as cool and reasonably dry.

May is in the spring in Glacier National Park and is typically the 5th warmest month of the year. Daytime maximum temperatures average around a cool 13°C (55°F), whilst at night 1°C (35°F) is normal.

On average May is the 2nd wettest month of the year in Glacier National Park with around 79mm 3.1 inches of rain making it a reasonably dry time to visit. This rainfall is typically spread over 10 days, although this may vary considerably.

On the flip side this corresponds to an average of 8.4 hours of sunshine per day.

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Glacier National Park in May 2025.