Average data for 10 years
1 September
Monday
+31°
+15°
2 September
Tuesday
+31°
+15°
3 September
Wednesday
+31°
+16°
4 September
Thursday
+30°
+15°
5 September
Friday
+31°
+15°
6 September
Saturday
+30°
+15°
7 September
Sunday
+30°
+15°
8 September
Monday
+30°
+15°
9 September
Tuesday
+30°
+15°
10 September
Wednesday
+29°
+14°
11 September
Thursday
+30°
+14°
12 September
Friday
+30°
+14°
13 September
Saturday
+30°
+14°
14 September
Sunday
+29°
+14°
15 September
Monday
+28°
+15°
16 September
Tuesday
+27°
+14°
17 September
Wednesday
+26°
+14°
18 September
Thursday
+26°
+14°
19 September
Friday
+26°
+13°
20 September
Saturday
+26°
+12°
21 September
Sunday
+25°
+11°
22 September
Monday
+26°
+12°
23 September
Tuesday
+26°
+12°
24 September
Wednesday
+26°
+12°
25 September
Thursday
+27°
+13°
26 September
Friday
+26°
+12°
27 September
Saturday
+26°
+12°
28 September
Sunday
+26°
+12°
29 September
Monday
+26°
+12°
30 September
Tuesday
+24°
+12°
In September, the weather in Hermiston is typically warm. Average daily high temperature in September is about 28 degrees above zero. On average, Hermiston has 21 sunny, 7 partly cloudy, and 2 rainy days in September. The rains are usually light. September as well as April and May is considered the most comfortable time to visit Hermiston.