Summer 2025 Start Date Usa. And the rest of the countries in the northern hemisphere, the summer solstice will begin on thursday, june. Summer of 2025 was 2.25 f (1.25 c) warmer than the average summer between 1951 and 1980, and august alone was 2.34 f (1.3 c) warmer than average.

Online calendar of holidays and days off in united states for the summer of 2025. Et on june 20, 2025, accordi n g to space.com.