When do seasons start?

[snopes]

Comment: We always hear about the "official" start of the seasons spring,
summer, winter and fall. The dates usually correspond to the twice-yearly
solstices and equinoxes. But is there really some governing body,
scientific or political, that has declared these dates as the start of the
next season?

[ganzfeld]

Originally Posted by snopes

Comment: We always hear about the "official" start of the seasons spring,
summer, winter and fall. The dates usually correspond to the twice-yearly
solstices and equinoxes. But is there really some governing body,
scientific or political, that has declared these dates as the start of the
next season?

Yes. His name is Punxsutawney Phil.

[Wild Redhead]

Originally Posted by ganzfeld

Yes. His name is Punxsutawney Phil.

Pfft. Everyone knows Mother Nature has the final say.

[llewtrah]

I had this debate with Tarquin. Spring may not officially begin till the calendar says it begins, but try telling the spring bulbs, blossoms and animals that! I spotted a pigeon laying eggs 2 weeks ago.

[Floater]

If you ask the meteorologists, who are the ones that should know, they would say that Winter is when the mean temperature over 24 hours is lower than 0C. Spring and Autumn is when the temperature is between 0 and 10C and Summer when the temperature is over 10C and these conditions must have been met for a period of at least 10 days. The calendar doesn't enter into it.

[llewtrah]

Originally Posted by Floater

If you ask the meteorologists, who are the ones that should know, they would say that Winter is when the mean temperature over 24 hours is lower than 0C. Spring and Autumn is when the temperature is between 0 and 10C and Summer when the temperature is over 10C and these conditions must have been met for a period of at least 10 days. The calendar doesn't enter into it.

I thought it was mean hours of daylight rather than temperature? Some countries don't get much in the way of temperature variations.

[jimmy101_again]

Originally Posted by Floater

If you ask the meteorologists, who are the ones that should know, they would say that Winter is when the mean temperature over 24 hours is lower than 0C. Spring and Autumn is when the temperature is between 0 and 10C and Summer when the temperature is over 10C and these conditions must have been met for a period of at least 10 days. The calendar doesn't enter into it.

That's an interesting definition. So the equator is summer nearly year round and the poles have no summer?

I believe the seasons are 100% based on the equinoxes and solstices. That is astronomy and not meteorology. Summer is the season with the most hours of daylight/day, winter the season with the fewest hours sunlight/day. So the equator and the poles (and everywhere in between) have equal length seasons.

[WildaBeast]

Originally Posted by Floater

If you ask the meteorologists, who are the ones that should know, they would say that Winter is when the mean temperature over 24 hours is lower than 0C. Spring and Autumn is when the temperature is between 0 and 10C and Summer when the temperature is over 10C and these conditions must have been met for a period of at least 10 days. The calendar doesn't enter into it.

By this definition, we don't have winter here at all, but if I drive about 90 minutes east to the mountians it is winter.