There are two ways to say when a season starts. Astronomical seasons begin at the solstices and equinoxes, set by the Earth's position around the Sun, so their dates shift slightly each year. Meteorological seasons start on the first day of a month (March 1, June 1, September 1 and December 1), which weather services use because it makes record-keeping simpler. Here are both, with exact dates for 2026 and 2027 in the Northern Hemisphere (US Eastern time).
First day of each season (astronomical)
| Season | Event | 2026 | 2027 |
|---|---|---|---|
| Spring | March equinox | Friday, March 20 | Saturday, March 20 |
| Summer | June solstice | Sunday, June 21 | Monday, June 21 |
| Fall | September equinox | Tuesday, September 22 | Thursday, September 23 |
| Winter | December solstice | Monday, December 21 | Tuesday, December 21 |
Each of these is an exact moment, not a whole day. Because the moment can fall late in the evening in one time zone and after midnight in another, the "first day" can differ by one date around the world. For example, the September 2026 equinox happens on the evening of September 22 in the US, and in the early hours of September 23 in Europe and Asia.
Meteorological seasons
| Season | Months | Starts |
|---|---|---|
| Spring | March, April, May | March 1 |
| Summer | June, July, August | June 1 |
| Fall (autumn) | September, October, November | September 1 |
| Winter | December, January, February | December 1 |
Meteorologists group whole months so they can compare seasonal temperature and rainfall statistics from year to year. These groupings also match the weather people actually experience better: in most of the US, early December feels more like winter than late September feels like summer.
What season is it right now?
As of early October 2026, it's fall in the Northern Hemisphere by both definitions. Astronomical fall began on September 22 and runs until the winter solstice on December 21. In the Southern Hemisphere (Australia, South Africa, Argentina), the seasons are reversed: it's spring there.
Why do we have seasons?
Seasons are caused by the tilt of the Earth's axis, about 23.4 degrees, not by how close we are to the Sun. In fact, the Earth is closest to the Sun in early January, during the Northern Hemisphere's winter. When your hemisphere tilts toward the Sun, sunlight hits it more directly and days are longer, so it warms up. When it tilts away, the light is spread over a larger area and days are shorter.
- At the solstices, one hemisphere is tilted as far as possible toward the Sun. The June solstice brings the longest day in the north; the December solstice brings the shortest. See our guide to the solstices.
- At the equinoxes, neither hemisphere tilts toward the Sun, and day and night are roughly equal everywhere. "Equinox" comes from the Latin for "equal night".
Why the dates change from year to year
A calendar year is 365 days, but the Earth's trip around the Sun takes about 365.24 days. The exact moment of each equinox and solstice therefore arrives about six hours later each year, then jumps back about a day when a leap year adds February 29. That's why the first day of spring can be March 19, 20 or 21, and the first day of fall can be September 22 or 23. Over this century, the dates are drifting slightly earlier because of how the Gregorian leap-year rule works.
Seasonal milestones and holidays
| Season | Popular milestones |
|---|---|
| Spring | Daylight saving time begins (2nd Sunday in March), St. Patrick's Day, Easter, Mother's Day |
| Summer | Memorial Day (unofficial start), Fourth of July, Labor Day (unofficial end) |
| Fall | Back to school, Halloween, daylight saving time ends (1st Sunday in November), Thanksgiving |
| Winter | Hanukkah, Christmas, New Year, Valentine's Day |
Many Americans also use cultural markers for summer: it "starts" with Memorial Day weekend and "ends" with Labor Day, regardless of the astronomical dates.
How long is each season?
Astronomical seasons aren't equal in length, because the Earth moves faster when it's closer to the Sun (in January) and slower when it's farther away (in July). In the Northern Hemisphere, summer lasts about 93.7 days and winter only about 89 days. Spring is about 92.8 days and fall about 89.8 days.
Count down: see exactly how many days remain until winter, spring, summer or fall, with live timers and the dates for the next six years.
Frequently asked questions
When is the first day of winter 2026?
Monday, December 21, 2026, at the winter solstice. Meteorological winter starts on December 1.
When does spring start in 2027?
Saturday, March 20, 2027, at the March equinox. Meteorological spring starts March 1.
Is fall the same as autumn?
Yes. "Fall" is more common in American English and "autumn" in British English; both refer to the same season.