Summer

Description: The seasons are popularly considered in some Western countries to start at the equinoxes and solstices, based on astronomical reckoning. Thus, in the Northern hemisphere, based on astronomy, summer begins on the day of the June solstice and ends on the September equinox. When it is summer in the northern hemisphere it is winter in the southern... ( +expand to view full text )

Description: The seasons are popularly considered in some Western countries to start at the equinoxes and solstices, based on astronomical reckoning. Thus, in the Northern hemisphere, based on astronomy, summer begins on the day of the June solstice and ends on the September equinox. When it is summer in the northern hemisphere it is winter in the southern hemisphere, and vice versa. But, because the seasonal lag is less than 1/10th of a year (except near large bodies of water), the meteorological start of the season, which is based on average temperature patterns, precedes by about three weeks the start of the astronomical season. According to meteorologists, summer extends for the whole months of December, January and February in the southern hemisphere, and the whole months of June, July and August in the northern hemisphere. This meteorological definition of summer also aligns with the commonly viewed notion of summer as the season with the longest (and warmest) days of the year, in which daylight predominates. From the astronomical perspective, spring days lengthen from equinox to solstice and summer days shorten from solstice to equinox, while meteorological summer encompasses the build-up to the longest day and a diminishing thereafter, so that summer has many more hours of daylight than spring.