Washington, DC Weather

Washington is in the humid subtropical climate zone . The Trewartha classification is defined as an oceanic climate (Do). Winters are usually cool with light snow, and summers are hot and humid. The district is in plant hardiness zone 8a near downtown, and zone 7b elsewhere in the city, indicating a humid subtropical climate.

Spring and fall are mild to warm, while winter is cool with annual snowfall averaging 15.5 inches (39 cm). Winter temperatures average around 38 °F (3 °C) from mid-December to mid-February. However, winter temperatures in excess of 60 °F (16 °C) are not uncommon.

Summers are hot and humid with a July daily average of 79.8 °F (26.6 °C) and average daily relative humidity around 66%, which can cause moderate personal discomfort. Heat indices regularly approach 100 °F (38 °C) at the height of summer. The combination of heat and humidity in the summer brings very frequent thunderstorms, some of which occasionally produce tornadoes in the area.

Blizzards affect Washington, on average, once every four to six years. The most violent storms are called “nor’easters”, which often affect large sections of the East Coast. From January 27 to 28, 1922, the city officially received 28 inches (71 cm) of snowfall, the largest snowstorm since official measurements began in 1885. According to notes kept at the time, the city received between 30 and 36 inches (76 and 91 cm) from a snowstorm in January 1772.

Hurricanes (or their remnants) occasionally track through the area in late summer and early fall. However, they are often weak by the time they reach Washington, partly due to the city’s inland location. Flooding of the Potomac River, however, caused by a combination of high tide, storm surge, and runoff, has been known to cause extensive property damage in the neighborhood of Georgetown.

Precipitation occurs throughout the year.

Washington’s climate will grow warmer and rainfall will increase as the result of climate change.

The highest recorded temperature was 106 °F (41 °C) on August 6, 1918, and on July 20, 1930. while the lowest recorded temperature was −15 °F (−26 °C) on February 11, 1899, right before the Great Blizzard of 1899. During a typical year, the city averages about 37 days at or above 90 °F (32 °C) and 64 nights at or below the freezing mark (32 °F or 0 °C). On average, the first day with a minimum at or below freezing is November 18 and the last day is March 27.

Average Temperature
Jan
39 °F
4 °C
Feb
45 °F
7 °C
Mar
48 °F
9 °C
Apr
68 °F
20 °C
May
77 °F
25 °C
Jun
82 °F
28 °C
Jul
88 °F
31 °C
Aug
84 °F
29 °C
Sep
82 °F
28 °C
Oct
66 °F
19 °C
Nov
50 °F
10 °C
Dec
46 °F
8 °C
Humidity
Jan
68%
Feb
65%
Mar
55%
Apr
60%
May
74%
Jun
65%
Jul
65%
Aug
67%
Sep
62%
Oct
65%
Nov
61%
Dec
69%
Rain
Jan
63mm
Feb
50mm
Mar
65mm
Apr
66mm
May
87mm
Jun
72mm
Jul
97mm
Aug
125mm
Sep
32mm
Oct
43mm
Nov
82mm
Dec
31mm
Clouds
Jan
55%
Feb
55%
Mar
41%
Apr
49%
May
45%
Jun
41%
Jul
16%
Aug
32%
Sep
22%
Oct
41%
Nov
31%
Dec
45%
Air quality US AQI
Jan
12
Feb
10
Mar
10
Apr
16
May
19
Jun
24
Jul
25
Aug
23
Sep
23
Oct
28
Nov
27
Dec
17
Sun
Jan
2UVI
Feb
4UVI
Mar
4UVI
Apr
6UVI
May
8UVI
Jun
8UVI
Jul
9UVI
Aug
8UVI
Sep
7UVI
Oct
4UVI
Nov
2UVI
Dec
2UVI