Average December Temperatures for Idaho

Average temperatures for December 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 December temperatures
High °F	Low °F	Place	High °C	Low °C
33	11	Driggs	0	-12
30	13	Idaho Falls	-1	-10
26	6	Island Park	-4	-14
34	16	Malad City	1	-9
36	21	Pocatello	2	-6
34	17	Preston	1	-9
29	13	Saint Anthony	-2	-10

Central Idaho

Average daily temperatures in December
High °F	Low °F	Place	High °C	Low °C
24	8	Craters of the Moon Monument	-4	-13
30	9	Ketchum	-1	-13
37	19	Lake Walcott, Minidoka Dam	3	-7
33	15	Middle Fork Lodge	1	-9
29	13	Salmon	-2	-11
36	24	St. Maries	2	-4
25	-2	Stanley, Sawtooth Recreation Area	-4	-19
37	21	Twin Falls	3	-6

Southwestern Idaho

December temperatures: daily averages
High °F	Low °F	Place	High °C	Low °C
39	25	Boise	4	-4
40	29	Brownlee Reservoir Dam	4	-2
43	26	Bruneau	6	-3
35	14	Idaho City	1	-10
40	24	Lake Lowell, Deer Flat Dam	5	-4
30	13	McCall	-1	-10
39	23	Mountain Home	4	-5

Northern Idaho

Average December temperatures
High °F	Low °F	Place	High °C	Low °C
33	24	Bonners Ferry	1	-5
36	26	Coeur d’Alene	2	-3
33	14	Elk City	1	-10
36	22	Kellogg	2	-6
41	30	Lewiston	5	-1
36	22	Moscow	2	-6
32	22	Mullan	0	-6
36	21	Porthill	2	-6
30	18	Powell	-1	-8
40	25	Riggins	4	-4
34	23	Sandpoint	1	-5
33	24	Wallace	1	-5

Average Temperatures for Idaho in December

Eastern Idaho

Central Idaho

Southwestern Idaho

Northern Idaho

Reference

More Idaho Weather Information