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
97°
73°
16
97°
77°
17
89°
72°
18
93°
67°
19
94°
67°
20
92°
69°
21
90°
67°
22
91°
71°
23
95°
71°
24
96°
73°
25
95°
71°
26
93°
70°
27
93°
70°
28
90°
67°
29
89°
68°
30
86°
63°
1
85°
65°
2
88°
64°
3
87°
64°
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 85° to 96°, with overnight lows between 63° and 73°. The average high for September is 91° with an average low of 68°. 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.
