Days Until Fall 2027: Countdown to the September Equinox

Fall 2027 starts on Thursday, September 23

The September equinox in 2027 falls on Thursday, September 23. From October 25, 2026 that is 333 days, or 47 weeks and 4 days, which comes to 7,992 hours. The arithmetic is easy to check by hand: 47 x 7 + 4 = 333. Divide the days by seven and the remainder tells you how far past a whole number of weeks you are.

Autumn 2026 is already under way. That equinox fell on Tuesday, September 22, 2026, which is 33 days before today, so the number worth watching is the one for the coming year. In every year on the table below the September equinox lands on September 22 or September 23 in the Eastern time zone, and this counter always points at the next autumn that has not started yet.

Counting to the meteorological start on September 1, 2027 gives 311 days, which is 44 weeks and 3 days, so the two calendars are 22 days apart at the start of fall. For the longer view, the 2028 equinox arrives on Friday, September 22, which is 698 days from October 25, 2026.

Two start dates: September 1 and the equinox

Meteorological fall covers September, October and November because whole months make climate records easy to compare. Astronomical fall starts at the equinox, the moment the sun crosses the celestial equator heading south. The National Centers for Environmental Information explains the split, and it is the reason the first day of fall keeps showing up as two different dates on two different calendars.

For 2027 the meteorological season runs from September 1 to November 30, which is 91 days. The astronomical season runs from the September 23 equinox to the December 21 solstice, which is 89 days. If the question is when fall starts for the sun, the equinox is the answer. If the question is when the season starts for a temperature record, September 1 is the answer.

Neither date is wrong, and the gap between them holds some of the best weather of the year, with the summer heat broken and the leaves still green.

How the counter rolls to the next autumn

The hard part of a fall countdown is that fall keeps arriving while the page sits there. A page that hard coded September 22, 2026 would read 0 days for the rest of that year and a negative number in January. This one compares the date you enter with the equinox for that year, and when the equinox is already behind you it moves to the following year instead.

That is why the same widget reads 333 days on October 25, 2026 and a different number on August 3 of the same year. The September 1 option follows the same rule, and the season length that comes back matches the year it lands on, so 2027 gives 89 days and 2028 gives 90.

Every date in the page is built at midnight UTC, and the equinox date is the Eastern time date, so the count lines up with the date printed on a US wall calendar. UTC is the time scale kept by the NIST time and frequency division, and it never observes daylight saving, so the count does not jump when the clocks change in November.

September equinox dates from 2026 to 2035

The equinox drifts about six hours later each year, because a calendar year is a little shorter than one orbit, and leap years pull it back. The National Weather Service publishes the Naval Observatory times in Eastern time, and the first rows below come straight from that table. Rows past 2030 convert the published UTC times to Eastern, which in September means subtracting four hours for daylight saving.

Three of those ten autumns begin on September 23 in the Eastern zone, in 2027, 2031 and 2035, and the other seven begin on September 22. The count column shows why the year matters: the gap from October 25, 2026 grows by 365 or 366 days at a time, so the 2035 equinox sits 3,255 days out. Published tables differ by a minute here and there, so the countdown works from the Eastern date only.

The pattern comes from the tropical year of 365 days and about 5 hours 49 minutes: that leftover takes four years to add up to a leap day, and a leap year puts the equinox about 18 hours earlier, which is enough to move the Eastern date back to September 22.

How fast the daylight fades after the equinox

Right after the equinox the sun's declination moves about 0.4 degrees a day, and the length of the day follows it down. How fast that happens depends on latitude: the farther north you live, the steeper the loss. The figures below come from the standard sunrise equation, without the corrections for refraction and the width of the solar disk, so a printed almanac will differ by a minute or two.

New York loses 2.8 minutes of daylight on the first day after the equinox, and 2.8 x 7 = 19.6 minutes over the first week. Seattle loses 3.5 minutes a day, and Miami, close to the tropics, loses only 1.6. Across the first 30 days New York gives up 81 minutes, Seattle 104 minutes and Miami 45 minutes.

This is the real reason fall feels short. The sun sets earlier every evening, and by the end of October a city near 40 degrees north has given up more than an hour and a half of usable light. The National Weather Service sunrise and sunset calculator gives local times for any date if you want to check a specific city.

Frost, leaves and the other fall clocks

Fall has dates that have nothing to do with the sun. The first freeze reaches the northern states while the leaves are still green, and the first frost along the Gulf Coast can wait until December or skip the year entirely. The table below gives a rough window for the first night at or below 32 degrees Fahrenheit in a typical year, plus the usual peak of the foliage.

Those windows move with a single cold snap rather than with the season, so treat them as a planning guide. The color works its way south as October turns into November, which is why an early October peak in New England and a late November peak along the Gulf Coast can both be called peak fall.

Trees respond to the shortening day more than to temperature, which is why a warm week in September does not hold the color back. A hard freeze ends the show quickly, because water in the leaves freezes and the leaves drop within days.

School year, fall sports and the heating season

Most school districts in the United States run about 180 school days and open in the second half of August, which puts the first day of classes a week or two before the meteorological start of fall. Football, soccer and cross country practice start in August as well, so the fall season in a town begins before the equinox does.

The other calendar is the heating season. A furnace that sat idle all summer needs a service visit in September, a filter change every 90 days and a chimney check before the first cold night. Filters are cheap next to a repair: a 3 inch filter costs about $15, and two of them cover a heating season, so 2 x 15 = $30 of filters protects equipment that costs many times that to replace.

A thermostat setback pays for itself in the same weeks. Dropping the set point 7 to 10 degrees for the 8 hours you are asleep or away is the standard advice, and the saving shows up first in November and December, when the system runs longest. A programmable thermostat does the same job without anyone remembering to turn a dial.

None of this waits for the equinox. The cold snap that ends the growing season reaches the northern plains in October and the Northeast in November.

Clocks go back on the first Sunday in November

Daylight saving time ends on the first Sunday in November, which in 2026 is Sunday, November 1, 7 days from October 25. The clocks move back an hour at 2 a.m., so sunset in New York moves from just before 6 p.m. on October 31 to just before 5 p.m. on November 1. In 2027 the same Sunday falls on November 7.

The date sits between the equinox and the winter solstice, 40 days after the September 22 equinox in 2026, and it is the point where the clock and the calendar disagree most. The sun keeps setting earlier for another seven weeks, and the hour handed back makes the dark arrive an hour sooner than the date alone would suggest.

Hawaii and most of Arizona stay on standard time all year, so nothing changes there. The NIST time description page explains how the civil clock is kept in step with UTC, and the equinox and solstice table on the National Weather Service seasons page covers the whole year.