Gaithersburg, Maryland, gets 40 inches of rain per year. The US average is 37. Snowfall is 19 inches. The average US city gets 25 inches of snow per year. The number of days with any measurable precipitation is 108.
On average, there are 202 sunny days per year in Gaithersburg, Maryland. The July high is around 87 degrees. The January low is 25. Our comfort index, which is based on humidity during the hot months, is a 44 out of 100, where higher is more comfortable. The US average on the comfort index is 44.