A summer solstice does not always fall on June 21. In the Northern Hemisphere, it can occur on June 20, 21, or 22.
The exact date shifts because the Gregorian calendar year has exactly 365 days, while Earth's actual orbit around the sun takes about 365.25 days. To keep the calendar aligned, leap years are added every four years, which causes the exact timing of the sun's most northern position to shift backward.
The astronomical start of summer is officially determined by exactly when the sun reaches its highest point, rather than a fixed calendar date. For the exact time and date of the solstice in your specific time zone, you can check the Almanac Time Zone Converter.
Historically, the solstice has been widely celebrated with festivals and bonfires. People traditionally gather at ancient sites to watch the sunrise, marking a cultural and historical connection to the changing seasons.
You can check out how the USA Today explains the event, or read about the astronomy behind it with the Facebook Post by The Weather Channel.
Would you like to know the exact number of daylight hours for your specific latitude in West Bronx, NY, or are you looking for local summer events and festivals happening nearby?