Weather 15 hours ago When is the autumnal equinox? An equal share of day and night Meteorological summer began on Sept. 1, but astronomical autumn is Sept. 22 at 8:44 a.m., what we call the autumnal equinox. US & World Videos 1:38 6 to know – Top stories of the day 1:40 Crews battle fire near Tropical Park in Southwest Miami-Dade 2:52 Mother dies month after daughter killed in Palm Beach County crash 1:53 FBI raid in Miami connected to crypto theft and laundering scam 2:34 Parents accused of child neglect express remorse after kid found wandering alone