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Climate guideThirty-year normals for Gaithersburg, Maryland
Gaithersburg climate by month
Humid subtropical · CfaBest Apr · Sep–Oct
Annual mean55°day and night
Seasonal swing43°warmest vs coolest
Precipitation44.3 in127 wet days a year
39.14° N, 77.20° WElevation 502 ftUTC−4 · Eastern Daylight Time
When to goGaithersburg · weather score
Best timeApr · Sep–Oct
October: high / low67° / 47°
iSummary
What the weather is like
Gaithersburg has a humid subtropical climate (Köppen Cfa): rain spread through the year and no real dry season.
The warmest month is July, when afternoons average 87° and nights 67°. January is the coolest month, with highs of 42° and lows of 25°. The difference between the warmest and the coolest month is about 43°, a large swing typical of continental interiors.
About 44.3 in of precipitation falls in an average year. July is the wettest month (4.1 in, 14 wet days) and November the driest (3.3 in, 8 wet days). Cloud cover ranges from 30% in July to 41% in February.
Compared with Washington, the capital, Gaithersburg is 1.3° cooler on a July afternoon and receives more precipitation over the year.
Year in figures
- Hottest afternoons
- 87° · July
- Coldest nights
- 25° · January
- Wettest month
- July
- Driest month
- November
- Clearest skies
- July · 30% cloud
- Longest day
- 14 h 54 min
- Shortest day
- 9 h 26 min
iiCharts
Twelve months at a glance
Temperature and precipitation
Daily high/low range bars, monthly precipitation columnsTemperature curve
Average high, lowDaylight
Hours between sunrise and sunset on the 15th of each monthiiiData table
Climate normals month by month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Average high | 42° | 45° | 54° | 66° | 74° | 82° | 87° | 85° | 78° | 67° | 56° | 46° |
| Average low | 25° | 27° | 34° | 43° | 53° | 62° | 67° | 65° | 58° | 47° | 37° | 30° |
| Precipitation | 3.1 in | 3.0 in | 3.6 in | 3.7 in | 4.6 in | 4.1 in | 4.1 in | 3.8 in | 3.9 in | 3.7 in | 3.3 in | 3.4 in |
| Wet days (≥1 mm) | 8.2 | 8.4 | 9.9 | 10.7 | 13.2 | 13.8 | 14 | 13.4 | 9.4 | 9.3 | 7.8 | 9.2 |
| Cloud cover | 40% | 41% | 40% | 38% | 37% | 33% | 30% | 30% | 34% | 32% | 37% | 40% |
| Daylight | 9h 43 | 10h 45 | 11h 55 | 13h 13 | 14h 19 | 14h 54 | 14h 40 | 13h 43 | 12h 28 | 11h 13 | 10h 03 | 9h 26 |
| Month score | 35 | 34 | 41 | 71 | 66 | 54 | 44 | 50 | 74 | 77 | 53 | 32 |
ivMonth by month
Gaithersburg in every month
January35
42° / 25°
3.1 in · 8.2 wet days
February34
45° / 27°
3.0 in · 8.4 wet days
March41
54° / 34°
3.6 in · 9.9 wet days
April71
66° / 43°
3.7 in · 10.7 wet days
May66
74° / 53°
4.6 in · 13.2 wet days
June54
82° / 62°
4.1 in · 13.8 wet days
July44
87° / 67°
4.1 in · 14 wet days
August50
85° / 65°
3.8 in · 13.4 wet days
September74
78° / 58°
3.9 in · 9.4 wet days
October77
67° / 47°
3.7 in · 9.3 wet days
November53
56° / 37°
3.3 in · 7.8 wet days
December32
46° / 30°
3.4 in · 9.2 wet days