Gaithersburg, MD climate
Gaithersburg has chilly, snowy winters and warm summers. A typical July afternoon reaches 86°, a January night drops to 25°, and about 33 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Gaithersburg feels like
Winter
Spring
Summer
Fall
Gaithersburg weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 42° | 25° | 3.1" | 10.6" | 11 | 8 | 25° – 41° |
| February | 45° | 27° | 2.7" | 7.9" | 11 | 9 | 25° – 44° |
| March | 53° | 33° | 3.8" | 6.8" | 11 | 5 | 38° – 53° |
| April | 65° | 43° | 3.5" | 0 | 13 | 0 | 50° – 60° |
| May | 74° | 52° | 4.4" | 0 | 15 | 0 | 58° – 70° |
| June | 82° | 61° | 4.3" | 0 | 12 | 0 | 68° – 76° |
| July | 86° | 66° | 4.3" | 0 | 11 | 0 | 71° – 79° |
| August | 84° | 64° | 3.8" | 0 | 12 | 0 | 70° – 77° |
| September | 78° | 58° | 4.3" | 0 | 10 | 0 | 64° – 72° |
| October | 67° | 46° | 3.8" | 0.3" | 11 | 0 | 52° – 63° |
| November | 55° | 36° | 3.2" | 0.7" | 9 | 1 | 39° – 51° |
| December | 46° | 29° | 3.6" | 6.3" | 11 | 4 | 28° – 48° |
| Year | 65° | 45° | 44.8" | 32.6" | 137 | 27 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Gaithersburg
Gaithersburg gets 45 inches of rain and melted snow a year. May is the wettest month and February the driest. Rain or snow falls on about 137 days a year. Snow covers the ground about 27 days of the year.
About 219 frost-free days a year
In half of years the last 32° night comes by April 1 and the first one by November 6. That leaves about 219 frost-free days for gardens, longer than 82% of U.S. towns.
Heating and cooling a home in Gaithersburg
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Gaithersburg, 78% of that work is heating and 22% is cooling.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Gaithersburg and its neighbors
Gaithersburg borders 6 towns with climate data. January nights across them vary by 0.4°. Flower Hill has the coldest January nights (25°) and Darnestown the hottest July afternoons (87°). Gaithersburg’s January low is 25° and its July high 86°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Gaithersburg compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Gaithersburg averaged 1.7° warmer than the 1900s. The biggest change is in December (+2.9°). The shift is larger than in 84% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Gaithersburg’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. December swings the most: between 1991 and 2020 its average temperature ranged from 28° to 48°. September is the most reliable, staying within 7°.
Common questions about Gaithersburg’s climate
What is the coldest month in Gaithersburg?
January, with a typical high of 42° and a low of 25°.
What is the hottest month in Gaithersburg?
July, with a typical high of 86° and a low of 66°. About 23 days a year reach 90°.
How much snow does Gaithersburg get?
About 33 inches in a normal winter, most of it in January.
When is the first frost in Gaithersburg?
In half of years the first 32° night comes by November 6, and the last spring frost by April 1.
What is the rainiest month in Gaithersburg?
May, with 4.4 inches of rain and melted snow. The year totals 45 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Gaithersburg itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Clarksburg 2.1 Ne, MD (7 mi, snow) and Rockville 1 Ne, MD (4 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.