The temperatures in Gaithersburg in September are comfortable with low of 17°C and and high up to 26°C.
You can expect about 3 to 8 days of rain in Gaithersburg during the month of September. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Gaithersburg in September 2025.
If you’re planning to visit Gaithersburg in the near future, we highly recommend that you review the 14 day weather forecast for Gaithersburg before you arrive.
Temperatures
26° / 17°
Rainy Days
6
Snowy Days
0
Dry Days
24
Rainfall
135
mm
Sun Hours
9.9
Hrs