S
M
T
W
T
F
S
30
87°
50°
31
85°
48°
1
75°
52°
2
73°
57°
3
83°
56°
4
84°
47°
5
75°
49°
6
73°
55°
7
82°
54°
8
83°
46°
9
73°
51°
10
72°
51°
11
72°
45°
12
70°
46°
13
70°
49°
14
71°
52°
15
76°
53°
16
79°
54°
17
81°
51°
18
78°
46°
19
69°
49°
20
73°
50°
21
71°
49°
22
75°
40°
23
65°
39°
24
63°
40°
25
68°
44°
26
62°
38°
27
61°
38°
28
Hist. Avg.
69°
45°
29
Hist. Avg.
68°
44°
30
Hist. Avg.
68°
44°
1
Hist. Avg.
68°
44°
2
Hist. Avg.
67°
43°
3
Hist. Avg.
66°
43°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Spearfish
Spearfish's September 2026 forecast shows daily high temperatures ranging from 61° to 87°, with overnight lows between 38° and 57°. The average high for September is 74° with an average low of 48°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Spearfish. See also: October | November | December.
