Boise, ID Weather by Month and Climate Averages

How much rain does Boise get?

Boise gets 11.5 in of precipitation in an average year, spread over about 89 days with measurable rain. That is more rainy days than 51% of the US.

December is the wettest month, with 1.5 in. August is the driest, with 0.2 in. December has the most rainy days, about 12.

The longest dry spell in the last five years lasted 50 days, to August 1, 2022.

See where Boise ranks: rainiest cities in the US, US cities with the most rainy days.

Does it snow in Boise?

Yes. Boise gets about 17.6 in of snow in an average season, measured at the reporting station.

The snowiest winter on record is 1985–86, with 39.6 in.

The most recent measurable snow at the station fell on April 2, 2026.

See where Boise ranks: snowiest cities in the US.

Boise weather by month

Boise weather in January

In January, Boise averages a high of 39°F and a low of 25°F. It gets 1.4 in of precipitation over about 11 rainy days. The sun is out about 36% of daylight hours. The January record high is 66°F (2024) and the record low is -14°F (1977).

Boise weather in February

In February, Boise averages a high of 46°F and a low of 29°F. It gets 1.0 in of precipitation over about 9 rainy days. The sun is out about 48% of daylight hours. The February record high is 71°F (1992) and the record low is -15°F (1989).

Boise weather in March

In March, Boise averages a high of 55°F and a low of 34°F. It gets 1.3 in of precipitation over about 10 rainy days. The sun is out about 46% of daylight hours. The March record high is 83°F (2026) and the record low is 6°F (1971).

Boise weather in April

In April, Boise averages a high of 62°F and a low of 39°F. It gets 1.2 in of precipitation over about 9 rainy days. The sun is out about 52% of daylight hours. The April record high is 92°F (1987) and the record low is 20°F (1975). April is one of the most comfortable months to visit.

Boise weather in May

In May, Boise averages a high of 72°F and a low of 47°F. It gets 1.4 in of precipitation over about 8 rainy days. The sun is out about 51% of daylight hours. The May record high is 100°F (2025) and the record low is 22°F (1982). May is one of the most comfortable months to visit.

Boise weather in June

In June, Boise averages a high of 81°F and a low of 54°F. It gets 0.8 in of precipitation over about 5 rainy days. The sun is out about 61% of daylight hours. The June record high is 110°F (2015) and the record low is 31°F (1984).

Boise weather in July

In July, Boise averages a high of 92°F and a low of 61°F. It gets 0.2 in of precipitation over about 2 rainy days. The sun is out about 84% of daylight hours. The July record high is 110°F (2013) and the record low is 35°F (1986).

Boise weather in August

In August, Boise averages a high of 91°F and a low of 60°F. It gets 0.2 in of precipitation over about 2 rainy days. The sun is out about 75% of daylight hours. The August record high is 110°F (2018) and the record low is 34°F (1992).

Boise weather in September

In September, Boise averages a high of 80°F and a low of 52°F. It gets 0.4 in of precipitation over about 4 rainy days. The sun is out about 74% of daylight hours. The September record high is 104°F (2022) and the record low is 23°F (1970). September is one of the most comfortable months to visit.

Boise weather in October

In October, Boise averages a high of 65°F and a low of 41°F. It gets 0.8 in of precipitation over about 6 rainy days. The sun is out about 63% of daylight hours. The October record high is 94°F (1992) and the record low is 11°F (1971). October is one of the most comfortable months to visit.

Boise weather in November

In November, Boise averages a high of 49°F and a low of 32°F. It gets 1.2 in of precipitation over about 10 rainy days. The sun is out about 46% of daylight hours. The November record high is 78°F (1999) and the record low is -3°F (1985).

Boise weather in December

In December, Boise averages a high of 39°F and a low of 25°F. It gets 1.5 in of precipitation over about 12 rainy days. The sun is out about 36% of daylight hours. The December record high is 63°F (1987) and the record low is -25°F (1990).

Sunshine, humidity and wind in Boise

July is the sunniest month in Boise, with sunshine about 84% of daylight hours. January is the cloudiest, at 36%. Over the year the sun shines about 56% of daylight hours. Boise is sunnier than 76% of the US.

Humidity peaks in January at 72% and is lowest in July at 25%.

Wind averages 7 mph over the year, and April is the windiest month at 9 mph.

Boise has about 52 days a year above 90°F. Boise is hotter than 70% of the US.

Thunderstorms occur on about 14 days a year.

See where Boise ranks: sunniest cities in the US, cloudiest cities in the US, hottest cities in the US.

First and last freeze in Boise

The first fall freeze in Boise typically comes around October 13, and the last spring freeze around May 4. That leaves a frost-free growing season of about 162 days.

Boise weather records

The hottest temperature on record at the Boise station is 110°F, on July 13, 2002. The coldest is -25°F, on December 22, 1990.

The wettest day on record brought 1.8 in of rain, on May 29, 1990.

45 all-time records have been set at the station since 1970.

The annual mean temperature has changed by +0.8°F per decade since 1970.

The best time to visit Boise

The most comfortable time to visit is typically April to May and September to October, when daytime highs sit near 70°F.

Winter (December–February) is chilly, with average highs around 41°F and lows near 26°F. Snow is possible.

Spring (March–May) is mild, with average highs around 63°F and lows near 40°F.

Summer (June–August) is hot, with average highs around 88°F and lows near 59°F.

Autumn (September–November) is mild, with average highs around 65°F and lows near 42°F.

Boise climate questions

How much rain does Boise get?

Boise gets 11.5 in of precipitation in an average year, over about 89 rainy days.

What is the wettest month in Boise?

December is the wettest month in Boise, with 1.5 in. August is the driest, with 0.2 in.

How many rainy days does Boise have a year?

Boise has about 89 days with measurable rain in an average year. December has the most, about 12.

Does it snow in Boise?

Yes. Boise gets about 17.6 in of snow in an average season. The snowiest winter on record is 1985–86, with 39.6 in.

What is the hottest month in Boise?

July is the warmest month in Boise, with an average high of 92°F.

What is the coldest month in Boise?

January is the coldest month in Boise, with an average low of 25°F.

What is the record high temperature in Boise?

The record high at the Boise station is 110°F, set on July 13, 2002. The record low is -25°F, on December 22, 1990.

What is the sunniest month in Boise?

July is the sunniest month in Boise, with sunshine about 84% of daylight hours. January is the cloudiest.

When is the first frost in Boise?

The first fall freeze in Boise typically comes around October 13. The last spring freeze is around May 4.

What is the best time to visit Boise?

The most comfortable time to visit is typically April to May and September to October, when daytime highs sit near 70°F.