It's worth noting that while the vernal equinox marks the beginning of spring in the astronomical sense, the meteorological definition of spring in Australia is often considered to start on September 1. This is because the Australian Meteorological Bureau uses this date to define the start of the spring season for the purposes of climate and weather forecasting.
In Australia , spring officially starts on . Unlike the Northern Hemisphere, where seasons are often defined by the astronomical equinoxes (roughly the 21st or 22nd of the month), Australia follows a meteorological seasonal system . This means every season starts on the first day of the respective month, with spring spanning exactly three months: September, October, and November . The Two Ways to Define Spring in Australia Definition Type Start Date Meteorological (Official) September 1 Grouping calendar months for easier statistical comparison. Astronomical September 22 or 23 when does spring start in australia