PHILADELPHIA (AP) — If the extreme heat baking much of the country wasn't enough of an indicator of summer's arrival, Mother Nature will make it official later Monday when the summer solstice marks the start of the season.
In the United States, summer begins at 6:34 p.m. on the East Coast.
"The Earth has arrived at a point around the sun that we receive the most sunlight," said Derrick Pitts, chief astronomer at The Franklin Institute science museum in Philadelphia.
Monday is the day that the Northern Hemisphere sees more hours of daylight than any other.
The days will begin to get measurably shorter next week. The number of hours of daylight will continue to shrink until Dec. 21, the winter solstice.
A full moon also coincides with Monday's solstice. June's full moon has traditionally been nicknamed the strawberry moon, a name Pitts said alludes to strawberry harvest season.
The moon will appear low in the sky for much of the night and could take on an amber hue because of atmospheric conditions.