Summer solstice 2021

The Summer solstice 2021 is on Monday, June 21, 2021 (in 244 days).  Calendar for 2021

The Summer solstice 2020 has already passed: it was on Saturday, June 20, 2020 (122 days ago).  Calendar for 2020

Please note: The dates given on this page are based on Coordinated Universal Time (UTC), which for practical purposes is equivalent to Greenwich Mean Time (GMT). While the Summer solstice occurs at the same moment in time all over the world, the date and local time differ from location to location depending on a location's time zone. For more details see the explanations below.

A summer solstice is the moment in time when the Earth's tilt towards the Sun is at its maximum and the Sun reaches its highest position in the sky.

A summer solstice occurs twice a year, once in June in the Northern Hemisphere (also called northern solstice, June solstice and Midsummer) and once in December in the Southern Hemisphere (also called southern solstice and December solstice).

In the Northern Hemisphere the day of the summer solstice is the longest day of the year (the day with the most daylight and the shortest night) and occurs every year between June 20 and June 22. The dates given on this page are based on Coordinated Universal Time (UTC), which for practical purposes is equivalent to Greenwich Mean Time (GMT - the time zone of the United Kingdom). While the summer solstice occurs at the same moment in time all over the world, the date and local time differ from place to place depending on the year and a location's time zone. For locations that are ahead of UTC (further east) it may fall on the day after, and for locations that are behind UTC (further west) it may fall on the day before. To find out the exact date and time of the summer solstice 2021 in your area use this seasons calculator.

The summer solstice marks the end of spring and the beginning of summer in the hemisphere where it occurs and is one of four days (two equinoxes and two solstices) throughout the year on which a new season starts. The other days are the vernal equinox (also called spring equinox, beginning of spring), the autumn equinox (also called fall equinox, beginning of autumn) and the winter solstice (beginning of winter).


The exact moment of the northern summer solstice through the centuries

Graph demonstrating the movement (caused by leap shifting) of the exact moment of the summer solstice between 1750 and 2250. X axis (bottom, horizontal): calendar years, Y axis (left, vertical): day in June (20th to 23rd).

In a non-leap year, the moment of the summer solstice is about 5 hours 49 minutes after that moment in the previous year (in UTC), and in a leap year it is about 18 hours 11 minutes before that moment in the previous year, as can be seen in this graph. In this way the time of the summer solstice constantly shifts back and forth so it always stays around June 20 to 22. This four year cycle is clearly visible in the graph.

To adjust for the gradual movement backwards on the calendar (as visible for the period 1900 to 2099), in years divisible by 100 (1800, 1900, 2100 and 2200 on the graph), which should be leap years as they are divisible by 4, the leap day is omitted (except when they are divisible by 400, eg. 2000) and the moment of the summer solstice moves forward in time compared to the same moment in the year before.

Further reading:
• Summer solstice on Wikipedia
• Solstices in general on Wikipedia

Overview: seasons, equinoxes and solstices

Dates shown apply to the Northern Hemisphere and are based on UTC (GMT)

Season	Start	End
Spring	Spring equinox (vernal equinox, March equinox) March 19 to 21	Summer solstice (June solstice) June 20 to 22
Summer	Summer solstice (June solstice) June 20 to 22	Autumn equinox (Fall equinox, September equinox) September 21 to 24
Autumn (Fall)	Autumn equinox (Fall equinox, September equinox) September 21 to 24	Winter solstice (December solstice) December 20 to 23
Winter	Winter solstice (December solstice) December 20 to 23	Spring equinox (vernal equinox, March equinox) March 19 to 21

The Summer solstice 2022 is on Tuesday, June 21, 2022 (in 609 days).  Calendar for 2022