Why we have Leap Years

Jesse Ferrell

Saturday is the first Feb. 29, or Leap Day, since 2016. So, why do we have Leap Years, anyway?

It's all because of the Earth's rotation and the fact that a day isn't actually an exact 24 hours. Slooh astronomer Bob Berman explained to AccuWeather, that each rotation of Earth takes 23 hours, 56 minutes and 4.1 seconds, to be precise. The orbit around the sun is also imprecise: Earth takes 365 days, five hours, 48 minutes and 45 seconds to complete a full trip.

The Gregorian calendar, created by Pope Gregory in 1583, factors in the uneven timing by including an extra day in February every four years as a leap year.

However, an extra day every four years is an overcorrection to the calendar, and Pope Gregory accounted for this, too. For every century year, the calendar resets by skipping leap year. Every 400 years, it does not reset and maintains the leap year. The year 2000 was a year that did not reset; therefore, it had an extra day.

Even though it only comes around every four, or so years, there have been some notable Leap Day events in weather history. Here are a few:

  • Hottest Leap Day: 100 degrees F at several towns in Texas -- Encinal, Mission, and Waslaco, in 1940.
  • Coldest Leap Day: -66 degrees F at Hughes, Alaska, in 1956.
  • Wettest Leap Day: 21 inches of rain at Puohokamoa, Hawaii, in 1984.
  • Snowiest Leap Day: 33 inches of snow at Cisco Grove, California, in 1944.

This week's lake-effect snow event is probably a little too early to break that snow record, although amounts may total 45 inches, the bulk of it will have fallen on this Friday, Leap Day Eve, if you will.

AccuWeather high-temperature forecast for Feb. 29, 2020

Forecast temperatures on Leap Day 2020 are expected to range from around 5 to 85 degrees, not threatening the records mentioned above. Other Leap Day tidbits of note:

  • In 1982, there was a tornado outbreak in Alabama, Tennessee, and Georgia. Four people were killed.
  • In 1976, Baltimore tied its record high when the mercury rose to 76 degrees F, while in 1956 a new record low was set at only 9 degrees F.
  • In 1992, Tropical Cyclone Esau was in the Coral Sea south of the Solomon Islands. Maximum sustained winds were 140 mph with gusts up to 175 mph.
  • In 2008, up to 14 inches of snow fell in Pennsylvania

There is also some interesting lore that is associated with Leap Day.

For instance, someone born on a Leap Day is known as a leapling, though the odds of being a leapling are exceedingly slim. The chances of being born on a leap day are about one in 1,461, according to the BBC. Leaplings typically celebrate their birthdays on Feb. 28 or March 1, iNews reports.

One Leap Day tradition includes a day on which women could break with custom and propose to their significant other. This is an old Irish legend that dates back to the 5th century and a deal struck by St. Patrick and St. Bridget. According to the Farmer's Almanac, St. Bridget came to St. Patrick frustrated with waiting for a man to propose to her. They came up with a deal that women could propose to a man only on a Leap Day.

The next leap day will be Thursday, Feb. 29, 2024.

Additional reporting by Lauren Fox.