Summer Solstice 20254 2025 Calendar. In 2025, the summer solstice in the northern hemisphere will occur on june 20, 2025, at 10:42 pm edt (or 2:42 am utc on june 21). It marks the longest day of the year and the arrival of the summer season.

The first day of summer (june solstice) is when the sun is in its most northern position directly over the tropic of cancer. For the northern hemisphere, the summer solstice can take place.