Boise (ID) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Boise.
Climate overview of Boise
Boise is the capital of the U.S. state of Idaho and is gaining attention for its vibrant cultural scene. It has a cold steppe climate, with an average annual precipitation of nearly 326 mm (13 in). Winters are quite cool, gloomy, and somewhat humid. The summer months, on the other hand, are warm, very sunny, and dry. During July and August, rain is rare, while the sun shines abundantly. July alone records up to 400 hours of sunshine (long-term average), contributing significantly to the annual total of nearly three thousand hours.
Boise Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Boise - and find the best time to visit.
Monthly Temperature in Boise
Visitors to Boise can expect significant temperature changes throughout the year. Average maximum daytime temperatures range from a very warm 34°C (93°F) in July, the warmest time of the year, to a chilly 4°C (39°F) during cooler months like January.
At night, you can expect temperatures ranging from 15°C (59°F) in July to around -5°C (23°F) during January.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Boise
Boise tends toward drier weather patterns, receiving approximately 326 mm (13 in) of rain/snow per year. Significant seasonal changes in precipitation occur throughout the year. In the wettest month, December it receives moderate snow/rainfall, averaging 49 mm (1.9 in) of precipitation, recorded across 14 snowy/rainy days. In contrast, the driest month August brings less rainfall, with 8.3 mm (0.3 in) over 4 rainy days. For more details, please visit our Boise Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in Boise
Seasonal changes in sunshine hours are quite dramatic in Boise. While July receives considerable daily sunshine with up to 13.3 hours, December marks the darkest time of the year, where sunshine is scarce with only 3.4 hours of sunlight per day.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Humidity in Boise by Month
The relative humidity is moderate throughout the year in Boise.
The city experiences its highest humidity in January, reaching 75%. In July, the humidity drops to its lowest level at 36%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Best Time to Visit Boise
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: May, June, September and October
- Warmest weather: July
- Most sunshine: July
- Fewest rainy days: July, August and September
- Seasonal pattern: Very little rainfall for most of the year, with very warm summers and cold winters
- Coldest conditions: January, with freezing nights around -5°C (23°F).
Frequently asked questions about the climate in Boise
What is the best time to visit Boise?
May, June, September and October typically offer the most optimal weather in Boise. In contrast, January, July, November and December tend to have less optimal conditions. Boise has very little rainfall for most of the year, with very warm summers and cold winters.
What temperatures can I expect in Boise?
Daytime highs range from 4°C (39°F) in January to 34°C (93°F) in July. Nighttime lows range from -5°C (23°F) to 15°C (59°F). Temperatures vary considerably through the year.
How much rain does Boise get?
Annual rainfall is around 326 mm (13 in). December is the wettest month with 49 mm (1.9 in), while August is the driest with 8.3 mm (0.3 in). In the coldest months, precipitation may fall as snow/rain.
How sunny is Boise?
Boise receives around 2,983 hours of sunshine per year. July is the sunniest month with 399 hours, while December is the cloudiest with just 103 hours. Overall, Boise enjoys abundant sunshine.
Boise 3-Day Forecast
Boise (ID) 3-Day Forecast
Boise on the map
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