The hours stated on weather maps at three hourly intervals. What do these times mean.?

Question

Weather

Answer 1

Usually the surface observations about the temperature, pressure,wind,humidity, cloud cover etc.,are taken in three hours interval (and at the same time)throughout the world and hence the maps are updated once in three hours.That time is given in the maps.

Answer 2

The times usually just denote when the map is valid or accurate.  They release them in increments to keep the most up to date weather conditions mapped.