This full-disk picture from NOAA’s GOES-13 satellite tv for pc was captured at 7:45 a.m. EDT (11:45 UTC) and exhibits the Americas on June 21, 2012, the beginning of astronomical summer time – within the Northern Hemisphere – that yr.
The primary day of summer time in 2025 is June 20; it is usually the longest day of the yr. Within the Southern Hemisphere, it’s the shortest day of the yr and the start of winter.
Earth orbits at an angle, so the Northern Hemisphere is tilted towards the Solar half of the yr — that is summer time within the Northern Hemisphere, and winter within the Southern Hemisphere. The opposite half of the yr, the Northern Hemisphere is tilted away from the Solar, creating winter within the north and summer time within the south. Solstices occur twice per yr, on the factors in Earth’s orbit the place this tilt is most pronounced.
Picture credit score: NASA