D.C. July outlook: The hottest in four or five years, with improving ...

2 days ago

The Washington Post

The average hottest month of summer is here for the D.C. area, following a June that already delivered significant summer heat and dryness.

For this month, we are favoring hotter than normal temperatures for Washington at about 2 to 3 degrees above the normal temperature of 81, which would be the hottest July in four or five years. After the very dry June, we are anticipating some catching-up this month for a tally near the normal of 4.33 inches of rain.

While these first days of July should end up drier than normal, late-week thunderstorm chances become a daily potential through next week.

The seven-day outlook from NOAA highlights the chance for some meaningful rain:

The latest 15-day outlooks from the American and European modeling systems are shown below. They feature normal to slightly hotter than normal temperatures with near to above normal rainfall.

We were tempted to flip July to a wetter-than-normal answer given this wetter first half potential. However, there may be more periods like June (hot/dry) later in this month to offset any wetter start.

For now, the longer-range weather models are wetter for the back half of July.

June recap

June 2024 included the first 100-degree Washington reading in nearly eight years (since August 2016). The 79.7 degree average temperature at Washington was 3.4 degrees hotter than normal and the second-hottest June on record after only 2010’s 80.6 degree average.

There were 15 days that reached at least 90 degrees, the fourth most on record. All of them happened from June 13-30, tying June 1994 for the most on record in that period.

The 1.15 inches of rain was the fourth driest on record, slightly higher than 2017’s 1.13. Dry and hot conditions through the month led to rapid drought expansion, although needed rain fell in some spots during the final days.

The month only experienced six days of measurable rainfall and just five days that were cooler than normal.

Several record highs were set around area airports during the hottest interval from June 22 to 26. Washington had its first low in the 80s since 2019, with a record warm 81 on the 23rd, which was among many record warm lows during the month.

Saturday, June 22:

Baltimore’s record high of 101 bested the 100 from 1988.Dulles’s record high of 100 bested the 101 from 1988.

Sunday, June 23:

Washington’s record high of 99 bested the 98 from 1988 and 1874.Baltimore’s record high of 98 bested the 97 from 2010 and 1894.Dulles’s record high of 98 bested the 96 from 1988 and 1965.

Wednesday, June 26:

Baltimore’s record high of 99 tied 1954 and 1952.Dulles’s record high of 99 bested the 95 from 1998.

We have been projecting a hot and drier-leaning summer, but the challenge has been navigating lingering influences from the departing El Niño climate pattern and incoming influences from a very slow-developing La Niña. Officially, the planet is still in-between, or in neutral conditions. However, a very strong negative Pacific Decadal Oscillation (PDO) condition may be providing more La Niña influences — hotter/drier — than we would typically see this early. That kept us cautious on rainfall thinking for July (near normal vs. above normal).

Year to date

With the hot and dry June, 2024 is now on pace for the second hottest on record, after only 2012.

Ian Livingston contributed to this report.