Bright colorful leaves are reflected in water at Speedwell Forge Lake Monday, Oct. 28, 2019.

Though temperatures are expected to mostly stay in the upper 70s and 80s in Lancaster County through the weekend, you may have noticed an proliferation of pumpkin spice drinks or that the mornings are a little darker.

They're all signs that fall is right around the corner.

This year, the astronomical start of fall starts Wednesday, September 22. Meteorological fall began on Sept. 1, and will run until Dec. 1, when meteorological winter begins.

Whereas astronomical seasons are based on the Earth's rotation around the sun, meteorologists break down the seasons into groupings of three months based on the annual temperature cycle and the calendar, according to National Centers for Environmental Information.

The autumnal equinox - or, the start of fall - is the day of the year where both day and night are around 12 hours long due to the Earth's 23.5-degree tilt and distance from the sun.

Daytime also begins to get progressively shorter − Tuesday will see 12 hours and 29 minutes of daylight, whereas the first day of fall will only see 12 hours and 8 minutes of daylight, according to TimeandDate.

The significance of the season

Before calendars, people used to keep their eyes to the skies to determine when the equinox was near. It's possible that Stonehenge was one of the structures that allowed people to tell when the sun rose exactly east and set west, according to History.com.

In some societies, fall was connected to spirituality and celebrating gods and goddesses. Other societies focused more on the harvesting and renewal parts of the season change.