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Seasons ·Solstice ·Astronomy

First day of summer 2026: When does summer officially start?

May 26, 2026·caldays editorial

The first day of summer 2026 in the Northern Hemisphere is Sunday, June 21, at exactly 08:25 UTC. This is the summer solstice — the longest day of the year, when the Sun reaches its highest point in the northern sky.

In the Southern Hemisphere, the first day of summer 2026 is Monday, December 21, at 20:50 UTC. Summer follows the Sun south during the December solstice.

Quick answer for both hemispheres

HemisphereFirst day of summer 2026Time (UTC)
NorthernSunday, 21 June 202608:25 UTC
SouthernMonday, 21 December 202620:50 UTC

For all four seasons in both hemispheres, see /seasons.

What exactly is the summer solstice?

The summer solstice is the moment when one of Earth's poles tilts most directly toward the Sun. In the Northern Hemisphere, this happens around June 20-22 each year. In the Southern Hemisphere, around December 20-23.

On this date:

  • The Sun appears at its highest point in the sky at noon.
  • Daylight is the longest of the entire year.
  • Above the Arctic/Antarctic Circle, the Sun never sets (the "midnight sun").

The word solstice comes from Latin sol (sun) + stitium (stop) — the Sun appears to "pause" in its northward (or southward) march before reversing direction.

Astronomical vs meteorological summer

There are two competing definitions:

Astronomical summer (what we use above) starts on the solstice — June 21 in 2026 (Northern Hemisphere). It ends on the autumn equinox, September 23.

Meteorological summer is a simpler system used by weather services: June 1 to August 31 (Northern), December 1 to February 28 (Southern). The simpler boundaries make seasonal climate statistics easier to compute and compare year-to-year.

So depending on who you ask, summer 2026 starts on June 1 (meteorological) or June 21 (astronomical).

Daylight on the summer solstice

How long is the day on June 21, 2026 in the Northern Hemisphere?

CitySunriseSunsetDaylight
Equator06:0018:0012h 00m
Mexico City05:5819:1413h 16m
New York05:2520:3115h 06m
London04:4321:2116h 38m
Reykjavik02:5500:04*21h 09m

\Reykjavik: actually only twilight, no full sunset above the Arctic Circle nearby.*

For your specific city's sunrise and sunset, use our sun times tool.

Cultural significance worldwide

The summer solstice is celebrated globally with millennia-old traditions:

  • Stonehenge sunrise — England — thousands gather pre-dawn for the alignment of the Heel Stone.
  • Midsommar — Sweden — second-most-important holiday after Christmas, with maypole dancing.
  • Inti Raymi — Peru — Inca Sun Festival, June 24 (winter solstice in Southern Hemisphere).
  • Litha — Wiccan/pagan — fire festivals and herb gathering.
  • International Yoga Day — UN-designated June 21 since 2015.

After the solstice: shorter days

After June 21, days start getting shorter (in the Northern Hemisphere) by about 1-3 minutes per day, accelerating into autumn. By the September equinox, day and night are roughly equal again.

The Sun's apparent path through the sky also drops lower toward the southern horizon each day. This is why shadows grow longer through autumn.

When are the other 2026 season starts?

In the Northern Hemisphere:

  • Spring equinox — Friday, March 20, 2026 at 14:46 UTC
  • Summer solstice — Sunday, June 21, 2026 at 08:25 UTC
  • Autumn equinox — Wednesday, September 23, 2026 at 00:06 UTC
  • Winter solstice — Monday, December 21, 2026 at 20:50 UTC

Southern Hemisphere is reversed: the September equinox is the start of spring, the December solstice the start of summer, and so on.

Related references


Astronomical season dates can vary by ±1 day depending on Earth's orbital position. Our values use IAU/NOAA published moments converted to UTC.

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