Summer Solstice Today: Heat Index Could Reach 103 Degrees

Summer officially arrives today at 7:08 p.m. EDT the time of this year's summer solstice, but rising temperatures Tuesday made it feel like it started a day early. 

Temperatures could reach 98 degrees with a heat index of 103 degrees in McLean and the Washington metro area today, according to the National Weather Service. (Increased humidity will make it feel like 103 degrees.) 

This will be the longest day of year. On Thursday, the days slowly start growing shorter. We don't tend to notice as we frolic and sweat through summer. Then toward the end of August, it occurs to us that night seems to be arriving a tad sooner.

Each year, the timing of the solstice depends on when the Sun reaches its farthest point north of the equator. This occurs annually on June 20 or June 21 in North America, depending on your time zone, according to the Farmer's Almanac.

The word solstice is from the Latin solstitium, from sol (sun) and stitium (to stop), reflecting the fact that the Sun appears to stop at this time (and again at the winter solstice), says the Farmer's Almanac.

Here's the week's torrid forecast:

Wednesday: Sunny and hot, with a high near 98. Heat index values as high as 103. Northwest wind between 3 and 7 mph.

Wednesday Night: Mostly clear, with a low around 76. West winds between 3 and 5 mph.

Thursday: Sunny and hot, with a high near 99. Heat index values as high as 104. Northwest winds between 5 and 7 mph.

Thursday Night: A slight chance of showers and thunderstorms before midnight. Partly cloudy, with a low around 75. West winds between 3 and 6 mph. Chance of precipitation is 20 percent.