Astronomical Autumn Arrives in Bulgaria
Astronomical autumn (fall) is arriving in Bulgaria Sunday, September 22 at 11:44 pm, the Institute for Astronomy and the National Astronomical Lab on peak Rozhen at the Bulgarian Academy of Sciences, BAS, announced.
This year September 22 is the day of the autumn equinox (it is always around this date) in the northern hemisphere, when night and day are nearly of the same length.
In the northern hemisphere, the Sun crosses the celestial equator moving southward. Daylight time becomes shorter and the weather starts to cool down.
In the southern hemisphere, the autumnal equinox corresponds to the center of the Sun crossing the celestial equator moving northward and occurs on the date of the northern vernal equinox, meaning spring begins in Australia and South America.
The autumn equinox marks the first day of the season of autumn.