When does summer start? What to know about the summer solstice in 2025
Summer is here, and it's about to get hot.
Today is the first official day of summer and if you don't know where the nearest pool is, it's time to find out before Indiana's anticipated hot weather sets in.
Friday, June 20, marks the first official day of summer in 2025. It's also the date of the summer solstice.
The first day of summer changes annually, arriving on June 20, 21 or 22. That's because the earth's astronomical year is actually 365.25 days long, writes Space.com.
The National Weather Service in Indianapolis predicts highs in the low to mid-90s this weekend and into Monday. The heat index, or how hot it really feels when you factor both temperature and humidity, could be in the low 100s through Tuesday, according to the NWS.
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The summer solstice, according to the National Weather Service, is when the earth's tilt toward the sun reaches its maximum noontime elevation. For everywhere north of the Tropic of Cancer, the sun is at its highest point in the sky, resulting in the longest day of the year.
Solstice is a combination of the Latin words sol, meaning "sun," and sistere, meaning "to stop," according to the Old Farmer's Almanac. It's derived from the Latin word solstitium. Or to put it in another way: solstice means "sun stands still."
In the northern hemisphere, summer begins near the end of June and lasts through July, August and most of September. On Sept. 22, the autumnal equinox marks the start of fall.
There are two solstices and two equinoxes every year, signaling the start of each new season. The summer solstice happens when the sun reaches its highest point in the sky and marks the longest day of the year. The winter solstice is when the sun hits its lowest point, resulting in the shortest day of the year.
Equinox means "equal night" in Latin, when nighttime and daytime are of equal lengths everywhere on the planet. Just like the solstice, there are two equinoxes — the vernal (first day of spring) and the autumnal (first day of fall).
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