WEATHER

First day of fall: Here's the exact time for the autumn equinox and what that means

Rashika Jaipuriar
Indianapolis Star

Get ready to fall into "Spooky Szn."

On Wednesday, the northern hemisphere will celebrate the autumn equinox, or the official beginning of fall.

Each year, the equinox occurs "at the exact same moment worldwide," according to the Old Farmer's Almanac, giving us about 12 hours of daytime and 12 hours of nighttime, depending on where you live. But they get pretty close to equal — the "total lengths may differ by only a few minutes," according to the Almanac.

"It’s not an all-day event such as a birthday or holiday,"  Almanac astronomer, Bob Berman, writes online (though fans of fall may disagree). And that's because in that one moment, the sun crosses the celestial equator, he explains, so the "Earth’s rotational axis is neither tilted away from nor towards the sun."

Wait, isn't Sept. 1 the start of fall? 

If you are a fan of the spooky season, and you've already broken out blankets and Halloween decorations, you're technically not too early.

The "meteorological" start of the season, determined by temperatures and the Gregorian calendar, did in fact begin on Sept. 1. Wednesday's equinox is the "astronomical" start of fall, which is based on the position of the sun.

This year, the equinox will take place on Wednesday at 3:20 p.m. After Wednesday, days will start becoming shorter than nights. That ends on Dec. 21 this year with the winter solstice, when days once again grow longer.

Winter in Indy:How Old Farmer's Almanac predictions have compared to actual Indianapolis winters

What will fall weather be like in Indiana this year?

The fall leaves are beautiful at Starve-Hollow State Recreation Area in Vallonia, Indiana.

October, on average, could be warmer than other years, according to the Indianapolis National Weather Service. In Central Indiana, there is a 50-60% chance of above average temperatures, Indianapolis NWS Meteorologist Aaron Updike explained.

A three-month outlook until about the end of November shows also shows a "slightly greater than normal chance" of above normal temperatures. "So leaning towards a 33 to 40% chance of having above normal temperatures," Updike said. But "that doesn't mean that we don't have cold stretches," he said, explaining that the probability looks at the average across several months. 

In Central Indiana, meteorologists are seeing "equal chances" of both higher precipitation or lower precipitation than usual. That means they're not quite certain about the precipitation outlook, Updike said.

When is the best time to see fall leaf colors in Indiana?

Though fall leaves may impacted by weather, they primarily change colors due to changes in sunlight and photosynthesis.

Fall colors:When and where Indiana's fall leaves will be at their peak across the state

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To see the best fall leaf colors in Indiana, mid- to late October will be the best time to see them, according to The Smoky Mountains Fall Foliage Prediction Map. That's when most of the state will hit "near peak" and "full peak" for leaves changing colors.

When do we turn the clocks back for the end of daylight saving time?

Not quite yet. The time change, when we reset our clocks one hour back to mark the end of daylight saving time, will happen on Sunday, Nov. 7. 

Contact Rashika Jaipuriar at rjaipuriar@gannett.com and follow her on Twitter @rashikajpr.