Click on a day for an hourly weather forecast
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.
Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
---|---|---|---|---|---|---|---|
January | 4° / -2° | 6 | 19 | 6 | 97 mm | Awful | Gaithersburg in January |
February | 6° / -1° | 7 | 15 | 6 | 115 mm | Awful | Gaithersburg in February |
March | 11° / 3° | 8 | 19 | 4 | 115 mm | Awful | Gaithersburg in March |
April | 18° / 8° | 7 | 23 | 0 | 121 mm | Ok | Gaithersburg in April |
May | 23° / 14° | 8 | 23 | 0 | 146 mm | Good | Gaithersburg in May |
June | 28° / 18° | 7 | 23 | 0 | 131 mm | Good | Gaithersburg in June |
July | 31° / 21° | 8 | 23 | 0 | 161 mm | Ok | Gaithersburg in July |
August | 30° / 21° | 7 | 24 | 0 | 154 mm | Ok | Gaithersburg in August |
September | 26° / 17° | 6 | 24 | 0 | 135 mm | Perfect | Gaithersburg in September |
October | 20° / 12° | 5 | 26 | 0 | 143 mm | Good | Gaithersburg in October |
November | 12° / 5° | 5 | 25 | 1 | 91 mm | Ok | Gaithersburg in November |
December | 7° / 2° | 6 | 21 | 4 | 124 mm | Bad | Gaithersburg in December |