When Does Fall Start 2018
In 2018, fall begins on different dates depending on the definition used. The astronomical start is tied to the autumnal equinox, while the meteorological start follows the calendar.
Autumnal Equinox Date
The astronomical fall of 2018 started on September 22, when the sun crossed the celestial equator moving southward. This event marks the moment of equal day and night length in both hemispheres.
Meteorological Fall Start
Meteorologists define fall as beginning on September 1 and ending on November 30. This calendar-based system aligns with temperature cycles and simplifies seasonal weather data comparison. For more details, see the National Oceanic and Atmospheric Administration guide on seasons at https://www.nesdis.noaa.gov/current-satellite-meteorological-products/seasonal-outlooks/seasonal-definitions.
