Defining The Seasons

Did you know there are official seasons? In fact two sets, one for the meteorologists and one for the astronomers. These are for the Northern Hemisphere.

Meteorologists:
Winter: December, January, February 

Spring: March, April, May 

Summer: June, July, August 

Autumn: September, October, November

Astronomers:
Winter: 22nd December (Winter Solstice) to March 20

Spring: March 21 (Spring Equinox) to June 20 

Summer: June 21 (Summer Solstice) to September 21 

Autumn: September 22 (Autumn Equinox) to 21 December

I offer instead, the Phenomenological Seasons:
Winter: when it starts to be cold all the time to when it stops being cold all the time, and there are no leaves except on evergreens 

Spring: when it's cold in the morning and evening, but warm-ish during the day, and the leaves appear

Summer: when I can wear a tee-shirt all day, and the leaves are all the same shade of green 

Autumn: see Spring, but the leaves are falling

Hence in the UK...
Winter is the five months from November to March (or, from when the clocks go back, to when the clocks go forward)

Spring is about eight weeks from April to May

Summer is the three months plus a week or so from June to sometime in September

Autumn is about six weeks from September to end-October