Friday is the longest day of the year north of the equator, where the solstice marks the start of astronomical summer.

The 2025 summer solstice takes place on June 20, heralding the onset of astronomical summer and the longest day of the year.

Summer officially began Friday in the Northern Hemisphere with the longest daylight of the year at around 15 hours.

This solstice falls between June 20 and 22. Meanwhile, at the winter solstice, the Northern Hemisphere is leaning away from the sun — leading to the shortest day and longest night of the year.

The 2025 summer solstice arrives at 10:42 p.m. EDT on June 20 (0242 GMT June 21). On this day, skywatchers across the northern hemisphere will enjoy the longest stretch of daylight all year.

Here’s how it works. Earth's tilted rotational axis places the sun high in the northern hemisphere's sky in June for the summer solstice. (Image credit: Albin Bonnard via Getty Images) ...

In the Northern Hemisphere, the summer season officially begins on the summer solstice. The day is full of festivities, sunshine, and the year's longest daylight hours.

The winter solstice has the least amount of incoming heat directly from sunlight. However, for nearly the whole of Australia, the coldest weather does not arrive when the days are shortest.