S
M
T
W
T
F
S
30
102°
82°
31
99°
81°
1
99°
77°
2
99°
72°
3
95°
66°
4
97°
72°
5
100°
68°
6
82°
72°
7
97°
68°
8
99°
73°
9
104°
81°
10
106°
84°
11
106°
84°
12
104°
81°
13
104°
81°
14
102°
73°
15
93°
75°
16
93°
70°
17
94°
71°
18
96°
68°
19
94°
69°
20
95°
69°
21
94°
71°
22
91°
72°
23
95°
71°
24
88°
68°
25
88°
67°
26
89°
66°
27
92°
67°
28
86°
65°
29
83°
60°
30
86°
63°
1
85°
65°
2
83°
60°
3
81°
60°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Boulder City
Boulder City's September 2026 forecast shows daily high temperatures ranging from 81° to 96°, with overnight lows between 60° and 75°. The average high for September is 90° with an average low of 67°. 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.
