S
M
T
W
T
F
S
30
78°
52°
31
78°
55°
1
69°
56°
2
71°
53°
3
72°
50°
4
71°
60°
5
71°
54°
6
68°
48°
7
68°
45°
8
79°
53°
9
81°
60°
10
64°
47°
11
64°
48°
12
66°
51°
13
66°
55°
14
65°
52°
15
64°
51°
16
66°
50°
17
63°
50°
18
63°
51°
19
65°
50°
20
66°
49°
21
66°
50°
22
63°
48°
23
61°
49°
24
60°
50°
25
63°
49°
26
60°
49°
27
58°
47°
28
56°
46°
29
56°
43°
30
54°
41°
1
54°
42°
2
55°
41°
3
56°
43°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Olsztyn
Olsztyn's September 2026 forecast shows daily high temperatures ranging from 54° to 66°, with overnight lows between 41° and 55°. The average high for September is 61° with an average low of 48°. 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 Olsztyn. See also: October | November | December.
