Climatological summer arrives with June — along with increasing heat, humidity and the front half of peak thunderstorm season.
There are occasional curveballs, often tied to our proximity to the much cooler Atlantic Ocean, which can send clouds and cooler air our way. But outside of those interruptions, the overall temperature trend is upward.
Average highs climb from about 81 degrees at the start of the month to 89 by the end. That late-June average is just one degree shy of July’s annual peak.
Normal and record daily temperatures
As average highs push through the 80s over the course of the month, June’s all-time record stands at 104 degrees, set in 2012 — the same day a violent and long-lived thunderstorm complex known as a derecho tore through the D.C. area.
Average lows begin the month in the lower 60s and climb to around 71 by the end. Record cool lows have dipped into the 40s, mainly during the first half of June. The all-time June low is 43 degrees, set in 1897.
Record daily precipitation
June has produced its share of heavy rain events, as thunderstorm season ramps up and cold fronts sometimes stall. The wettest June day on record produced 6.11 inches of rain on June 21, 1972 as the remnants of Hurricane Agnes came through.
Monthly temperatures by the year
June’s average temperature of 76.6 degrees makes it the third-warmest month of the year. The hottest June on record was 2010, with an average temperature of 80.6 degrees, while the coolest was 1907 at 65.9 degrees.
Monthly precipitation by the year
June averages 4.2 inches of precipitation, making it the second-wettest month of the year, just behind July. The wettest June on record came in 2006, when 14.02 inches fell, while the driest was 1940 with just 0.86 inches.
Days at or above 90
The 90-degree season ramps up in June, which averages seven to eight days at or above 90. The record is 18 such days, set in 2012 and previously in 1943. In some years — most recently 1979 — June did not reach 90 degrees at all.
There has been relatively little trend in the number of June 90-degree days since observations shifted from downtown D.C. to National Airport (DCA).
Thunderstorm frequency by day
Thunderstorm season aligns closely with D.C.’s warmest and wettest stretch of the year. At the start of June, there’s roughly a 1-in-5 historical chance of a thunderstorm on any given day. By the end of the month, that rises to about 1 in 4.
June may hold a slight edge over July when it comes to widespread damaging storm complexes, such as the one that struck on June 29, 2012.
Events of note
June 1, 2012. Nine confirmed tornadoes touched down in one of the region’s largest outbreaks in recent history. Tree damage was widespread, but structural damage was limited.
June 4, 2008. Multiple rounds of storms moved through the region, producing widespread power outages from wind gusts of 50 to 80 mph. Several tornadoes also occurred.
June 5, 2024. At least 13 tornadoes touched down across Maryland, Virginia and West Virginia. The nine in Maryland ranked among the top five daily tornado events in the state.
June 9, 1928. A tornado tore through Hains Point, destroying 11 aircraft at Bolling Field.
June 14, 1989. Wind gusts topped 80 mph in Northwest Washington and Bethesda. At the time, it marked the most significant damage to Pepco’s system on record.
June 21, 1972. The remnants of Hurricane Agnes produced one of the region’s worst floods. More than a foot of rain fell in spots, including a June-record 6.11 inches in D.C.
June 25, 2006. More than 9 inches of rain fell over two days ending June 26, including 5.19 inches on the 25th. Widespread flooding prompted a state of emergency in D.C. as slow-moving thunderstorms produced intense rainfall.
June 26, 1954. A derecho swept through the area, killing four people. Amid widespread wind damage, a gust of 66 mph was recorded in D.C. following a high near 100 degrees.
June 27, 1978. A violent nighttime storm — described as the worst in two decades — swept through the region, felling thousands of trees. A gust of 80 mph was recorded at Dulles Airport.
June 29, 2012. After a record June high of 104 degrees, a long-lived derecho that developed in the Midwest roared through the region. Widespread gusts of 60 to 80 mph uprooted trees and caused extensive damage. Five people were killed, and more than a million lost power.
Data sources include Applied Climate Information System and Iowa Environmental Mesonet.
