Average September Temperatures for Montana

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

You can jump to a separate table for each region of the state: Northwestern, Southwestern, South - Central and Eastern Montana.

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.

Northwestern Montana

Average September temperatures
High °F	Low °F	Place	High °C	Low °C
69	40	Cut Bank	20	5
63	38	East Glacier Park	17	3
68	36	Gibson Reservoir Dam	20	2
70	38	Kalispell	21	4
78	41	Libby	25	5
73	42	Missoula	23	6
70	32	Polebridge	21	0
71	46	Polson	22	8
70	41	Rogers Pass	21	5
73	37	Seeley Lake	23	3
68	41	West Glacier	20	5
69	40	Whitefish	20	5

Southwestern Montana

Average daily temperatures in September
High °F	Low °F	Place	High °C	Low °C
72	40	Anaconda	22	4
71	42	Bozeman	22	6
69	37	Butte	21	3
70	35	Deer Lodge	21	1
71	39	Dillon	22	4
76	44	Gardiner	24	7
68	37	Hebgen Lake Dam	20	3
73	45	Helena	23	7
73	34	Sula	23	1
71	41	Virginia City	22	5
68	30	West Yellowstone	20	-1

South - Central Montana

September temperatures: daily averages
High °F	Low °F	Place	High °C	Low °C
76	49	Bighorn Lake, Yellowtail Dam	25	9
74	49	Billings	24	9
62	31	Cooke City	17	0
66	42	Mystic Lake	19	5
71	42	Red Lodge	22	5

Eastern Montana

Average September temperatures
High °F	Low °F	Place	High °C	Low °C
76	44	Culbertson	24	6
74	43	Elwell Lake, Tiber Dam	23	6
77	48	Fort Peck Lake Dam	25	9
73	47	Glasgow	23	8
76	48	Glendive	25	9
72	43	Great Falls	22	6
73	43	Havre City	23	6
70	42	Lewistown	21	5
76	47	Miles City	24	8

Average Temperatures for Montana in September

Northwestern Montana

Southwestern Montana

South - Central Montana

Eastern Montana

Reference

More Montana Weather Information