Average data for 10 years
1 September
Sunday
+28°
+22°
2 September
Monday
+27°
+22°
3 September
Tuesday
+27°
+22°
4 September
Wednesday
+26°
+21°
5 September
Thursday
+26°
+22°
6 September
Friday
+26°
+21°
7 September
Saturday
+27°
+22°
8 September
Sunday
+28°
+23°
9 September
Monday
+27°
+22°
10 September
Tuesday
+28°
+23°
11 September
Wednesday
+28°
+23°
12 September
Thursday
+27°
+22°
13 September
Friday
+26°
+21°
14 September
Saturday
+26°
+20°
15 September
Sunday
+26°
+21°
16 September
Monday
+25°
+20°
17 September
Tuesday
+25°
+20°
18 September
Wednesday
+25°
+20°
19 September
Thursday
+24°
+19°
20 September
Friday
+23°
+19°
21 September
Saturday
+23°
+19°
22 September
Sunday
+23°
+19°
23 September
Monday
+22°
+18°
24 September
Tuesday
+23°
+19°
25 September
Wednesday
+24°
+19°
26 September
Thursday
+23°
+20°
27 September
Friday
+24°
+20°
28 September
Saturday
+22°
+18°
29 September
Sunday
+22°
+18°
30 September
Monday
+21°
+17°
In September, the weather in Hermiston is typically warm. Average daily high temperature in September is about 25 degrees above zero. On average, Hermiston has 26 sunny and 4 partly cloudy days in September. September as well as May and June is considered the most comfortable time to visit Hermiston.