As the entirety of the United States lies in the Northern Hemisphere, the first day of summer comes on either 20 or 21 June. This is the Summer Solstice, which has more daylight hours than any other day of the year. In the US, this day has about 14.5 hours of sunshine, though it varies from region to region. Summer officially ends at the Autumnal Equinox on 22 or 23 September.
|2020||20 Jun||Sat||First Day of Summer|
|2021||20 Jun||Sun||First Day of Summer|
|2022||20 Jun||Mon||First Day of Summer|
Meteorologists and most Americans tend to use other systems for delineating summer, however. The complete months of June, July, and August are considered summer under this way of thinking. Also, traditionally, some consider summertime to commence on Memorial Day, which falls on the final Monday in May, and run until the first Monday of September, which is Labor Day in the US.
Finally, summer break for school children also tends to delineate “summer” for many US residents. School dates vary, but most kids go on summer vacation in late May to mid-June and go back to school somewhere between early August and early September.
Summer is the season of the highest heat, greatest humidity, and longest days in the US. It is also the beginning of hurricane season along the US Atlantic and Gulf Coasts, where most US hurricanes occur. Hurricane season runs from the beginning of June till the end of November, but most activity takes place from mid-August through late October. Summer thunderstorms and tornados are also quite common, with the Plains States and South bearing the brunt of tornado season.
Regionally, summer conditions vary greatly across the US, which is to be expected since it spans many hundreds of miles from north to south and from east to west. In the Central Plains region, summers tend to be hot and humid. The South is similar, only a bit more intense. Far-south areas like Florida, South Texas, and Southern California are the hottest in the US and get prolonged and severe hot spells during summer months.
In the northeast, summers are warm but often with relatively cool morning hours and still-pleasant evenings. The Pacific Northwest follows a similar pattern, but it tends to get more rain.
Important summer holidays in the US include Memorial Day, Father’s Day, Independence Day, and Labor Day.