The temperatures in Rockville in September are comfortable with low of 17°C and and high up to 26°C.
You can expect rain for roughly half of the month of September in Rockville. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
Our weather forecast can give you a great sense of what weather to expect in Rockville in September 2025.
If you’re planning to visit Rockville in the near future, we highly recommend that you review the 14 day weather forecast for Rockville before you arrive.
Temperatures
26° / 17°
Rainy Days
8
Snowy Days
0
Dry Days
22
Rainfall
125
mm
Sun Hours
7.2
Hrs