Average Temperatures for Idaho in September





Average temperatures for September at cities, towns, parks and lakes throughout Idaho are listed below in degrees Fahrenheit and Celsius.

You can jump to a separate table for each region of the state: Eastern, Central, Southwestern and Northern Idaho.

The tables give the normals for maximum and minimum temperatures based on weather data collected from 1991 to 2020 by the US National Centers for Environmental Information.

Eastern Idaho

Average September temperatures
High °F Low °F Place High °C Low °C
73 38 Driggs 23 3
75 41 Idaho Falls 24 5
68 32 Island Park 20 0
78 41 Malad City 26 5
78 49 Pocatello 26 9
77 43 Preston 25 6
73 41 Saint Anthony 23 5

Central Idaho

Average daily temperatures in September
High °F Low °F Place High °C Low °C
69 38 Craters of the Moon Monument 21 4
69 36 Ketchum 21 2
78 44 Lake Walcott, Minidoka Dam 26 7
76 39 Middle Fork Lodge 24 4
74 41 Salmon 24 5
75 44 St. Maries 24 7
70 25 Stanley, Sawtooth Recreation Area 21 -4
76 45 Twin Falls 24 7

Southwestern Idaho

September temperatures: daily averages
High °F Low °F Place High °C Low °C
80 53 Boise 27 11
83 55 Brownlee Reservoir Dam 28 13
84 49 Bruneau 29 9
77 36 Idaho City 25 2
80 49 Lake Lowell, Deer Flat Dam 27 9
72 36 McCall 22 2
82 48 Mountain Home 28 9

Northern Idaho

Average September temperatures
High °F Low °F Place High °C Low °C
73 45 Bonners Ferry 23 7
74 48 Coeur d’Alene 23 9
74 32 Elk City 23 0
73 41 Kellogg 23 5
80 52 Lewiston 26 11
76 40 Moscow 25 4
71 42 Mullan 22 5
74 42 Porthill 23 6
71 37 Powell 21 3
80 45 Riggins 26 7
72 42 Sandpoint 22 6
71 44 Wallace 22 7
Reference

NOAA National Centers for Environmental Information (NCEI). Climate Normals.

Idaho Temperatures
Back to Top