The National Weather Service in Sterling, Virginia, has determined that this summer ranks as the sixth-hottest in records dating back to 1872. The temperature has averaged 79.1 degrees, which is 2.3 degrees above normal.

High temperatures have ranked 11th-warmest, and low temperatures seventh-warmest, the Weather Service said.

Temperatures trend higher today and even higher tomorrow. The weekend could be exceedingly hot, with the humidity remaining a force throughout.

The heat index tells you how it feels outside in the shade," the Maryland Department of Health and Mental Hygiene says on its website. "The heat index is a measurement of how it feels when relative humidity is combined with the effects of the air temperature."

We’ve logged 23 days at or above 90 degrees, which is six above normal for the year to date and ties for the 18th most on record through this point in the summer. In July, all but four days so far have hit at least 90.

Dulles and Baltimore have also posted warmer-than-normal conditions:
  • Dulles’s average temperature so far of 74.9 degrees ranks tenth warmest in records dating to 1963. It has tallied 16 days at or above 90 degrees, which is tied for 14th on record.
  • Baltimore’s average temperature of 75.7 degrees ranks 35th warmest dating to 1871. It has logged 19 days at or above 90, tied for 21st most.

Six of the 10 warmest first halves of summer in Washington have occurred since 2010: 2010 (hottest), 2011 (third hottest), 2012 (fourth hottest), 2017 (sixth hottest), 2015 (eighth hottest), 2014 (ninth hottest).

Until then, here are some ways to avoid heat-related illnesses:

  • Drink plenty of water and avoid drinks that have a lot of caffeine or large amounts of sugar.
  • Wear lightweight clothing and apply sunscreen.
  • Avoid excessive physical activity.
  • Do not keep children or pets in vehicles.
  • Keep cool indoors.
There is some good news. In the next two weeks, we'll lose 23 minutes of daylight, which will help average temperatures start to go down.

If you're a senior citizen, you're going to want to get your lifetime parks pass before August 28.