S
M
T
W
T
F
S
30
67°
47°
31
66°
47°
1
67°
54°
2
73°
55°
3
64°
53°
4
65°
53°
5
64°
47°
6
66°
50°
7
67°
48°
8
65°
49°
9
64°
45°
10
64°
45°
11
66°
43°
12
61°
44°
13
62°
45°
14
65°
46°
15
64°
41°
16
60°
40°
17
57°
39°
18
58°
40°
19
57°
41°
20
58°
43°
21
58°
40°
22
64°
40°
23
65°
47°
24
64°
47°
25
65°
46°
26
61°
47°
27
64°
38°
28
61°
35°
29
53°
36°
30
54°
45°
1
58°
46°
2
60°
46°
3
62°
45°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Portneuf
Portneuf's September 2026 forecast shows daily high temperatures ranging from 53° to 73°, with overnight lows between 35° and 55°. The average high for September is 63° with an average low of 45°. 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 Portneuf. See also: October | November | December.
