The concept of “season” depends on which system you’re using. There are two common definitions:
- Astronomical seasons: defined by equinoxes and solstices. Spring begins at the vernal (spring) equinox, summer at the summer solstice, autumn at the autumnal equinox, and winter at the winter solstice. The dates shift slightly each year (roughly March 20-21, June 20-21, September 22-23, December 21-22 in the Northern Hemisphere).
- Meteorological seasons: fixed three-month blocks aligned with the calendar year. Spring is March–May, summer is June–August, autumn (fall) is September–November, and winter is December–February. This system is commonly used for weather reporting and climate statistics.
If you’re asking specifically “when is season,” here are quick, practical takeaways:
- If you want the current season in the U.S. (or many places in the Northern Hemisphere) by astronomical convention, use the equinoxes and solstices dates for the current year. In 2025, spring starts around March 20–21, summer around June 20–21, autumn around September 22–23, and winter around December 21–22.
- If you want a simple, calendar-based answer (meteorological), seasons run exactly as: spring March–May, summer June–August, autumn September–November, winter December–February.
If you’d like, specify your location and whether you prefer astronomical or meteorological definitions, and the exact dates for the current year can be provided.
