Weather in Boise in August 2025
Average weather
Average temperature in Boise in August
Going from a maximum of +39°C during the day to a minimum of +12°C during the night, the temperature in August averages around +33°C.
The average maximum temperature goes down 15% by the end of the month, compared with the beginning of the month, from +36°C to +32°C.
Is Boise warm or cold in August?
Boise is typically hot in August.
Maximum temperatures go down compared to the previous month from +34°C to +33°C. The minimum temperature also goes down from +17°C to +16°C.
Make sure that you pack your summer linen and swimming costumes; it’s probably going to be hot.
August is one of the warmest months in Boise, here is the comparison with other months:
Climate in Boise in August
| July | August | September | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +34°C | +33°C | +28°C | ||||
| Min. temperature | ||||||
| +5°C | +5°C | 0°C | ||||
| Max. temperature | ||||||
| +43°C | +42°C | +40°C | ||||
| Rainfall | ||||||
| 5 mm | 9 mm | 17 mm | ||||
| Wind | ||||||
| 2 m/s | 2 m/s | 2 m/s | ||||
| Humidity | ||||||
| 33% | 34% | 41% | ||||
| Air pressure | ||||||
| 1010 HPa | 1010 HPa | 1012 HPa | ||||
| Sunny days | ||||||
| 23 | 22 | 21 | ||||
| Cloudy days | ||||||
| 3 | 4 | 4 | ||||
| Rainy days | ||||||
| 4 | 4 | 5 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
August weather is still as good as in July. It’s getting colder in August. From +34°C in the day, the average maximum temperature lowers to +33°C. Prepare for more rain. Average rainfall goes from 5 mm to 9 mm. Humidity rises from 33% to 34%. The average wind speed doesn’t change much during August, staying around 2 m/s. The days becoming less sunny, going from 23 sunny days in July to 22 in August.
But maybe it is worth considering traveling in September as the weather gets better.
Wind
The average wind speed is 3 m/s getting up to 4 m/s which is a light breeze; barely moving the tree leaves.
The average wind speed in Boise is gradually increasing during August, going from 2 m/s to 3 m/s over the course of the month.
Rain
How was the weather last August in Boise?
Climate Change over Years
The climate in Boise in August has not changed much over the last 43 years.
The average temperature was the lowest in 1985 (+16°C) and the highest in 2012 (+20°C). The driest year was 2002 with only 219 mm of rainfall, and the wettest year was 2024 with 653 mm.
FAQ
Is August a good time to visit Boise?
Can you sunbathe in Boise in August?
Is Boise rainy in August?
Is it sunny in Boise in August?
Other cities in USA
Monthly weather in Boise
Source of the data
For this page, we’ve looked at the typical weather in Boise, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.
