Afternoon begins at 12:01 p.m. and ends at 6 p.m. Many people think that sunset is the end of the afternoon, but that means that the end of the afternoon can be anywhere from 5 p.m. in the middle of winter to 9:30 p.m. in the middle of summer.
Meteorological time, which must be the same everywhere for forecasting, is one way to figure out when morning, afternoon, evening, and night start and end. Meteorologists think of the time between 6 a.m. and 12 p.m. as morning. From 12 to 6 p.m., it’s afternoon. From 6 p.m. to midnight, it’s evening. From midnight to 6 a.m., it’s nighttime.