Average May Temperatures for Idaho

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

Average Temperatures for Idaho in May

Eastern Idaho

Central Idaho

Southwestern Idaho

Northern Idaho

Reference

More Idaho Weather Information