Average Temperatures for Idaho in May

Average temperatures for May 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 May temperatures
High °F Low °F Place High °C Low °C
65 35 Driggs 18 2
67 38 Idaho Falls 20 4
59 32 Island Park 15 0
70 39 Malad City 21 4
71 44 Pocatello 21 7
69 40 Preston 21 5
65 39 Saint Anthony 18 4

Central Idaho

Average daily temperatures in May
High °F Low °F Place High °C Low °C
61 33 Craters of the Moon Monument 16 1
62 35 Ketchum 16 2
70 41 Lake Walcott, Minidoka Dam 21 5
67 38 Middle Fork Lodge 19 3
68 40 Salmon 20 4
68 42 St. Maries 20 6
60 26 Stanley, Sawtooth Recreation Area 16 -3
68 43 Twin Falls 20 6

Southwestern Idaho

May temperatures: daily averages
High °F Low °F Place High °C Low °C
72 48 Boise 22 9
74 50 Brownlee Reservoir Dam 23 10
76 48 Bruneau 24 9
66 35 Idaho City 19 1
73 46 Lake Lowell, Deer Flat Dam 23 8
61 35 McCall 16 2
74 45 Mountain Home 23 7

Northern Idaho

Average May temperatures
High °F Low °F Place High °C Low °C
69 43 Bonners Ferry 21 6
66 44 Coeur d’Alene 19 7
63 33 Elk City 17 0
69 40 Kellogg 20 4
72 48 Lewiston 22 9
67 38 Moscow 20 3
65 40 Mullan 19 5
71 42 Porthill 22 6
64 35 Powell 18 2
71 41 Riggins 22 5
66 42 Sandpoint 19 5
65 41 Wallace 18 5
Reference

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

Idaho Temperatures
Back to Top