Weather in Washington in July

United States · 20-year averages, July

Shoulder season. July is shoulder season in Washington — cheaper, quieter, and a genuine gamble. Highs average 31.1 °C, lows 21.1 °C, and rain falls on 14 days — nothing in the month is working against you.

July ranks 9 of 12 in Washington: past the worst of the year but short of October, which is the month to book if the dates are open.

Rain on 14 days, 3 of them heavy. Enough to need a plan B, not enough to need a plan around it. Pack for 31.1 °C days and 21.1 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: 20 days top 30 °C, making the heat continuous rather than occasional. Across the twenty years measured, the hottest July day reached 40.7 °C and the coldest night fell to 13 °C, and the wettest single day dropped 101 mm — roughly 87% of the month's rain in one day.

July is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest July on record still delivered 248 mm against 58 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 116 mm average is a reasonable planning figure, not a promise.

Wind is light at 7.2 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 69%.

How July sits in the year

Temperatures hold steady either side: 28.1 °C in June, 31.1 here, 30.6 in August. Nothing about the timing within the month matters much.

Daylight in July

July is at or near the longest days of Washington's year: 14.7 hours of daylight, losing 0.6 hours across the month. Evenings are the real gain — dinner outdoors still happens in full light.

An inland climate

With no coast nearby, the year swings a fair way — 34.4 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage.

How busy it gets

Busy. Popular without being frantic; book the things you care about, improvise the rest.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

July in Washington versus nearby

If Washington is one option among several, the nearby comparison is worth making. Richmond is a better bet in July — 9.7 °C cooler, 9 days less rain. Philadelphia is close enough to be a coin toss — within a degree on temperature, the same number of rain days.

So: July is a compromise. October is 26 points better and is what Washington is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Washington

MonthHigh °CLow °CRain daysRain mmHumidity %Daylight hScore
January4.8-3.3 867829.730
February6.5-2.6 9708010.736
March11.61.2 9847911.955
April18.17 10927613.274
May23.112.8 131107814.375
June28.118.1 141187414.967
July31.121.1 141166914.755
August30.620.6 131107013.759
September27.116.7 101077212.579
October20.210 91057611.381
November13.53.8 8807910.162
December7.5-0.5 995839.539

See all twelve months in Washington, or where else to go in July.

Planning the rest of the trip

Built and maintained by Amit Sharma, Auckland, New Zealand. I build these sites so the answer is free and the data is public.

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