S
M
T
W
T
F
S
30
76°
41°
31
77°
42°
1
78°
43°
2
81°
45°
3
82°
46°
4
84°
50°
5
86°
49°
6
85°
41°
7
81°
49°
8
82°
45°
9
72°
43°
10
70°
42°
11
72°
47°
12
75°
46°
13
73°
49°
14
72°
38°
15
70°
40°
16
76°
36°
17
74°
40°
18
75°
38°
19
Hist. Avg.
68°
34°
20
Hist. Avg.
68°
34°
21
Hist. Avg.
68°
34°
22
Hist. Avg.
67°
33°
23
Hist. Avg.
67°
33°
24
Hist. Avg.
66°
33°
25
Hist. Avg.
66°
33°
26
Hist. Avg.
66°
32°
27
Hist. Avg.
65°
32°
28
Hist. Avg.
65°
32°
29
Hist. Avg.
64°
32°
30
Hist. Avg.
64°
31°
1
Hist. Avg.
64°
31°
2
Hist. Avg.
63°
31°
3
Hist. Avg.
63°
31°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Lost River
Lost River's September 2026 forecast shows daily high temperatures ranging from 70° to 86°, with overnight lows between 36° and 50°. The average high for September is 77° with an average low of 44°. 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 Lost River. See also: October | November | December.
