Yesterday was one of those rare June days when in a single 24-hour period, residents of Washington could experience two seasons and one sensation: discomfort. At 6:11 p.m., spring ended, summer began, and the humidity was about as sticky as it can get.

Many of the ingredients of summer have been here for weeks or at least days: blistering heat, closed schools and heavy traffic on the way to the beach. Yesterday, the heavens made it astronomically official with the arrival of the summer solstice.

At 6:11 p.m., eastern daylight time, the Earth reached the point on its orbit at which the Sun stood above the Tropic of Cancer, or at least appeared to. That is as far north as the Sun goes -- or appears to -- before heading back across the Equator to the Tropic of Capricorn, and starting over again.

Yesterday's high temperature was 89, just below the 90-degree level that seems to symbolize summer suffering. The real story was the humidity.

In a description of yesterday's conditions, the National Weather Service said that "passing thunderstorms added more moisture to the already soggy air, making the air thick with the humidity and approaching the unbearable range."

Air conditioning made the day bearable for many Washingtonians. But the storms knocked out power for part of the day for about 3,000 Northern Virginia residents, and about 750 in Fort Washington, utility company spokesmen said.

Although clouds made it difficult to tell, yesterday was the longest day of the year, with 14 hours and 54 minutes of daylight.