Summer 2026 in the Northern Hemisphere starts on Sunday, June 21, 2026.

Astronomical vs. meteorological summer

  • Astronomical summer (what most “first day of summer” calendars show) begins at the summer solstice, which in 2026 falls on June 21 in the Northern Hemisphere.
  • Many weather and climate services also use meteorological summer, defined as June, July, and August, so that version of “summer 2026” starts on June 1, 2026.

Time and time zones

  • One source notes the solstice (start of astronomical summer) as June 21, 2026 at 08:25 GMT, which is early morning in U.S. time zones.
  • Others list similar early-morning times (for example, around 6:24 AM EDT in the U.S.), all corresponding to that same June 21 solstice moment.

Quick reference table (Northern Hemisphere)

[6][5][1][3] [7][5]
DefinitionStart of summer 2026Notes
Astronomical summer Sunday, June 21, 2026 (summer solstice) Longest day of the year, marks official seasonal change.
Meteorological summer Monday, June 1, 2026 Used by climatologists; runs June–August.

Information gathered from public forums or data available on the internet and portrayed here.