S
M
T
W
T
F
S
30
95°
70°
31
94°
70°
1
97°
71°
2
99°
72°
3
99°
75°
4
98°
71°
5
99°
75°
6
99°
73°
7
96°
71°
8
92°
71°
9
91°
68°
10
90°
69°
11
89°
68°
12
88°
73°
13
90°
74°
14
89°
71°
15
88°
69°
16
95°
68°
17
93°
65°
18
Hist. Avg.
90°
71°
19
Hist. Avg.
90°
70°
20
Hist. Avg.
89°
70°
21
Hist. Avg.
89°
70°
22
Hist. Avg.
88°
69°
23
Hist. Avg.
88°
69°
24
Hist. Avg.
88°
68°
25
Hist. Avg.
87°
68°
26
Hist. Avg.
87°
68°
27
Hist. Avg.
86°
67°
28
Hist. Avg.
86°
67°
29
Hist. Avg.
86°
66°
30
Hist. Avg.
85°
66°
1
Hist. Avg.
85°
66°
2
Hist. Avg.
84°
65°
3
Hist. Avg.
84°
65°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Boulder City
Boulder City's September 2026 forecast shows daily high temperatures ranging from 88° to 99°, with overnight lows between 65° and 75°. The average high for September is 94° with an average low of 71°. 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 Boulder City. See also: October | November | December.
