Saturday marks the summer solstice, the longest day of the year

Fifteen hours, 3 minutes and 49 seconds.

That’s how much daylight the Pittsburgh region will see today during the summer solstice — the official start of summer and longest day of the year, when the sun takes the northernmost path through the sky. The result is short nights, early dawns and late sunsets.

Facts and figures

The official start of summer for Pittsburgh, or the time the sun will be directly above the Tropic of Cancer — the point 23.5 degrees north of the equator — will be 5:44 p.m. The exact time varies by location, but 5:44 p.m. is the average starting point for the solstice in the Northern Hemisphere.

Solstice

According to the Farmer’s Almanac, solstice comes from the Latin words sol (sun) and sistere (to stand still). At the time of the solstice, the angle of the sun’s rays and the plane of the Earth’s equator gives the illusion they are standing still.

The illusion is most noticeable at the Arctic Circle when the sun sits along the horizon for 24 hours.

‘Ring of Fire’

A rare phenomenon will occur during this year’s solstice resulting in a solar eclipse that will be visible to people in parts of Africa and Asia. According to NASA, it will begin at 11:45 p.m. Saturday and end at 5:34 a.m. Sunday.

The annular eclipse can occur only when the moon is in its first lunar phase, and it must be farther away from Earth on its elliptical orbit, CBS News reports.

This causes the moon to appear smaller, meaning it cannot fully block out the sun, resulting in a “ring of fire.”

June 20

The earliest date the summer solstice typically occurs. The solstice has landed between June 20-22 since 1753, the year after Britain abandoned the Julian calendar for the Gregorian version, according to Timeand Date.com.

Changing weather

While the solstice marks the first day of summer, it does not mean it will be the hottest day of the year.

USA Today reported there is about a one-month lag between the event and peak summer temperatures.

Still, according to the National Weather Service, highs in the Pittsburgh region are expected to reach 84 on Saturday and 88 on Sunday with a chance of thunderstorms.