Temperature in Idaho in September

Daytime highs, nighttime lows and the warmest cities in Idaho, the United States of America this September.

Idaho, the United States of America, a region in the United States of America, experiences maximum daytime temperatures in September ranging from 20°C (68°F) in Wallace to 28°C (82°F) in Hagerman. Nighttime temperatures generally drop to 8°C (46°F) in Hagerman and 7°C (45°F) in Wallace.

What is the temperature of the different cities in Idaho, the United States of America in September?

Explore the map below to discover average September temperatures at the top destinations in Idaho. For a deeper dive, simply click on any destination dot.

Select a Month

Check the conditions for any month of the year.

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For a detailed overview over the year and the best time to visit Idaho, check out our Idaho's climate page.

See also: Idaho weather by month.

Best Places to Visit in Idaho in September

Click on a destination dot for more details. Toggle the map to compare temperatures or precipitation across Idaho.

Conditions Temperatures Precipitation
Avg daytime high -5°C (23°F) cold → 32°C (90°F) hot

Marker color shows the average daytime high temperature in September: blue is cold, red is hot.

See all September weather averages, cities and regions in Idaho

Idaho temperatures in September: frequently asked questions

How hot does it get in Idaho, the United States of America in September?

Average daytime highs in Idaho, the United States of America during September reach about 27°C (81°F) in Boise.

How cold does it get at night in Idaho, the United States of America in September?

After dark, Boise cools to about 10°C (50°F) on an average September night.

What is the warmest city in September in Idaho, the United States of America?

Data insights from our comprehensive database indicate that Hagerman is the city with the highest warmth. Daytime peaks average near 28°C (82°F), while the nights are characterized by a low temperature close to 8°C (46°F).

What is the coldest city in September in Idaho, the United States of America?

For the month of September, Wallace is the most temperate city in Idaho, the United States of America based on our records. Highs average 20°C (68°F) and nighttime temperatures dip to around 7°C (45°F).

How much sun does Idaho, the United States of America get in September?

The weather is predominantly sunny, with an estimated total of around 303 hours of sunshine in Boise. This means many sunny days, which creates a cheerful atmosphere during this month.

Interested in more climate information?

We have much more information about the climate in Idaho.

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