Summer officially began in Philadelphia at 6:07 a.m. Thursday. The sun rose at 5:33 a.m. and will set at 8:33 p.m. and here in the northern hemisphere we will enjoy more hours of daylight and fewer hours of darkness than any other day this year.
Also known as the summer solstice, this is the day each year when the sun is directly over the Tropic of Cancer due to the tilt of Earth on its axis. This provides maximum hours of sunlight north of the equator. The farther north, the more hours of sunlight you will have.
Here in Philadelphia we will have 15 hours of sunlight and the longest hours of twilight after the sun sets. Across the Arctic Circle the sun never really sets and there will be 24 hours of sunlight. The opposite effect happens on the Winter Solstice each December when we see the fewest hours of sunlight and the greatest hours of darkness.
The summer Solstice can occur on June 20, 21 or 22 of any given year. Next year in 2019 it once again falls on June 21.
The weather on our first day of summer will be seasonal with low to mid-80s, isolated showers early in the morning and skies clearing to sunshine by mid-day.