SACRAMENTO, Calif. — Meteorologists have been tracking climate and weather stats using full calendar months dating back to the mid-20th century.
June, July and August are all officially summer, according to the meteorological calendar. This helps when it comes to tracking any changes to data like temperature and precipitation.
Astronomical summer is what has been used in the form of solstices and equinoxes. Solstices are in summer and winter. Equinoxes are in the spring and fall. The summer solstice is when the tilt of the earth lines up directly with the sun around June 21, reaching the highest position in the sky.
Summer solstice is the longest daylight of the year in the Northern Hemisphere. People could see anywhere from 14.5 hours of daylight in Los Angeles to as much as 24 hours of daylight in the Arctic, depending on your proximity to the equator.
During winter solstice, the sun is at its lowest elevation in the sky, which causes less daylight around December 21.
These dates -- June 21 and December 21 -- use the alignment of the sun and earth to determine the start of summer and winter. But these dates are changing all the time even if only by a day or two. Climate data can be calculated inaccurately with the date of summer solstice frequently changing to account for leap year.