S
M
T
W
T
F
S
30
63°
48°
31
63°
47°
1
64°
47°
2
62°
48°
3
62°
48°
4
63°
46°
5
63°
44°
6
64°
44°
7
62°
50°
8
62°
49°
9
65°
47°
10
63°
48°
11
62°
50°
12
61°
49°
13
62°
46°
14
62°
45°
15
60°
46°
16
61°
50°
17
61°
45°
18
63°
47°
19
61°
49°
20
62°
49°
21
63°
48°
22
63°
49°
23
62°
47°
24
61°
48°
25
61°
48°
26
60°
47°
27
60°
47°
28
61°
46°
29
61°
45°
30
57°
44°
1
58°
46°
2
60°
42°
3
Hist. Avg.
58°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Castle Douglas
Castle Douglas's September 2026 forecast shows daily high temperatures ranging from 57° to 65°, with overnight lows between 42° and 50°. The average high for September is 62° with an average low of 47°. 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 Castle Douglas. See also: October | November | December.
