S
M
T
W
T
F
S
30
105°
79°
31
92°
80°
1
101°
80°
2
103°
87°
3
103°
85°
4
104°
84°
5
101°
83°
6
106°
83°
7
108°
82°
8
109°
88°
9
107°
90°
10
108°
89°
11
106°
84°
12
103°
85°
13
103°
85°
14
104°
81°
15
100°
81°
16
100°
80°
17
104°
82°
18
106°
81°
19
104°
78°
20
102°
78°
21
98°
75°
22
97°
75°
23
98°
77°
24
94°
71°
25
90°
65°
26
96°
74°
27
98°
73°
28
94°
73°
29
93°
72°
30
97°
72°
1
97°
71°
2
96°
72°
3
97°
71°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Surprise
Surprise's September 2026 forecast shows daily high temperatures ranging from 90° to 106°, with overnight lows between 65° and 85°. The average high for September is 99° with an average low of 76°. 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 Surprise. See also: October | November | December.