When is the first day of fall? Plus, climate shifts and what to expect in Rochester this season
"Autumn in New York. Why does it seem so inviting?"
When is fall in Rochester and western New York, officially?
Meteorological autumn (different from standard/astronomical autumn) began Sept. 1 and ends Nov. 30.
But we're almost at astronomical fall seasons — the autumnal equinox is the day that at a precise moment each September, usually on the 22nd or 23rd, the sun is directly above the equator.
This year, on Sept. 23, the center of the sun will be directly over the equator at 2:50 a.m. EDT, according to EarthSky.com. In the Northern Hemisphere, the sun will get lower in the sky and daylight will become shorter until the winter solstice on Dec. 21.
Day and night aren't exactly 12 hours long on the day of the equinox because the Earth's atmosphere refracts, or bends, light in an optical illusion that brings more daylight than there really is, as Janet Loehrke and Doyle Rice lay out in this excellent graphic explainer in USA TODAY.
Because of this, the date when day and night are of exactly equal length is usually a few days after the autumnal equinox.
What causes the seasons to change?
Earth has seasons because of its tilted axis, which is at 23.5 degrees to its orbit. As the planet revolves around the sun, the axis points in the same direction. On Sept. 23, day and night are roughly equal in length.
Climate does have an effect on how we experience fall in western New York.
Temperature: Autumn temperatures have increased by 2.7 F on average across America since 1970, postponing the "cool trigger that plants need to start shutting down," according to Climate Central. The nonprofit tracks research on climate change and how it affects people's lives.
"Unusually hot fall days now happen more often in 231 locations," said the data site. "And 86 locations now experience at least two more weeks of above-normal fall days than in 1970."
Expect warmer fall weather in Rochester NY
Will it be warmer this fall in Rochester and the Finger Lakes than when we were kids?
Yes. The average temperature has risen steadily every year for decades in Rochester, due to carbon emissions. In this area "a typical fall day" is up 2 degrees or more since the disbanding of The Beatles (also since Diana Ross made her big movie debut playing Billie Holiday).
How much snow will we get this winter?: Here's what the Old Farmer's Almanac predicts
So, how we experience the autumn season is slowly changing, which experts predict will lead to cultural and lifestyle changes over generations.
What can we expect in fall's weather forecast?
For now, here is how the National Weather Service describes fall in Rochester, New York.
Does it sound right to you?
"Autumn is pleasant, but rather brief. Mild and dry conditions predominate through September and much of October, but colder airmasses cross the Great Lakes with increasing frequency starting in late October, and result in a drastic increase in cloud cover across the region in late October and early November."
Although the first frosts may not occur until late October along the lakeshores, the first lake effect snows of the season follow soon thereafter. ..usually by mid November.
The growing season is relatively long for the latitude, averaging about 180 days.
The long growing season, combined with ample spring moisture and abundant summer sunshine ... is beneficial for the many fruit orchards and wineries, especially near the Lake Ontario shore and the Finger Lakes.
Wait for the colder weather to settle in
Accuweather's seasonal forecast calls for a delay in typically chilly weather.
Read a foliage explainer here and find out where fall colors are nearing their peak in New York here.
"One of the driving factors behind the weather patterns across the U.S. this autumn will be El Niño, a regular climate pattern that can reshape the jet stream. El Niño developed early this year when the water near the equator in the eastern Pacific Ocean warmed to at least 0.9 F above the historical average. The pattern replaced its cooler counterpart, La Niña, which persisted for three consecutive years."
More: Where is the peak foliage in NY? Latest foliage report and map
"Other factors have weighed on the minds of forecasters, including sea surface temperatures in the Atlantic and what has transpired in previous years when conditions were similar," reads the report from a team including meteorologists Brian Lada and Paul Pastelok.
This week, you can expect a run of almost flawless days to continue. In Rochester, Wednesday, Sept. 20, for example, was brilliant, pointed out Democrat and Chronicle Executive Editor Mike Kilian.
Enjoy the days.
"It's autumn in New York / It's good to live it again!"
More: What kind of summer was it outside in Rochester? These 2 facts might surprise you.
USA TODAY contributed information for this story, including Janet Loehrke and Doyle Rice.
The Democrat & Chronicle has been investigating the effects of a rapidly heating planet on people who live in our city. Follow along with "City on Fire" as we report the struggle with summer temperatures caused by climate crisis. This is part of the USA TODAY project Perilous Course. Check out the podcast by D&C journalist Rob Bell or contact William Ramsey for general climate impact story ideas.
This article originally appeared on Rochester Democrat and Chronicle: When is the first day of fall 2023? Autumn weather prediction for NY
