In my country the dates you stated are what are considered the start of the seasons. This year there was a very clear change between winter and spring on March 1st. February was cloudy and minus, March was sunny and plus.

Ocean currents, elevation and distance from the equator also have a big impact on what the season is going to feel like.

There's no need to change the dates. They're already arbitrary based on the position of the sun and the earth and people have the experience to take them with the grain of salt necessary to the region they live in. People who live near the equator probably don't have much care for the notion of the winter at all. Folks who live far up north know that spring actually comes in much later than march 21st. People who climb glaciated mountains in the canadian rockies know they won't get summer conditions until late june.

funny how this is actually the default for me having grown up in Ukraine.

probably same for other post-soviet countries too?

I second this proposal. Three weeks shift can feel about right.

But we lost a lot of nice symmetries that way, which is unfortunate

> I would propose boundaries that align partly with how I perceive the weather, and partly with how we plan our year (by months): Summer starts June 1st, Fall starts September 1st, Winter starts December 1st, and Spring starts March 1st.

You do realize there's also a southern hemisphere on planet Earth?

Hottest day of the year in the US varies by 3 months from California to Texas, which is only about half the width of the country. I would imagine the region you're in has a different hottest day of the year from say Kashmir or your neighbor Sri Lanka.

Europe does not. Summer is June, July and August with a bit of give here and there.

We were taught the same (Australian) - though it always felt slightly off as March often has major heatwaves, and December can be quite spring-like, often cool and wet.

Adelaide’s climate anecdotally feels to be more humid in recent years (historically bone dry Mediterranean climate) and the seasons feel like they’ve shifted a few weeks forward.

The Kaurna (Australian Aboriginal people of Adelaide, pronounced Gar-nuh) apparently mapped seasons a little differently, with a longer summer that resonates with my experience:

https://www.bom.gov.au/resources/indigenous-weather-knowledg...

The Noongar people of Western Australia have a 6 season model that also maps pretty well to my experience in South Australia.

https://australiassouthwest.com/six-seasons-of-the-south-wes...

Part of the reason for this is that climate lags behind sunlight a bit, so the end of the authors "summer" would be warmer than the beginning.

But most countries other than the USA use meteorological definitions of the seasons starting on the 1st of December, March, June, and September.

I find the "solstices/equinoxes mark starts of seasons" a bit foreign too, but… weather-wise, annual top and bottom temperatures are of course offset from the solstices due to thermal inertia.

In Finland the traditional division is that winter is Dec-Feb, spring is Mar-May, summer is Jun-Aug, and autumn is Sep-Nov. Historically it has made perfect sense, weather and climate wise – particularly from the point of view of agriculture, which is of course the reason people used to think about seasons in the first place!

February in particular is 100% winter in Finland with no signs of spring besides the days starting to get very noticeably longer by then. It's often the coldest month of the year and when schools usually have a week-long winter break. Similarly, August is very definitely a summer month except in the far north where spring comes late and autumn early. The academic year in schools and universities typically starts at the end of August, so that's a clear and important dividing line in many people's lifes. In Southern Finland, December is these days rather autumny more often than not, and there's often no lasting snow until January (if even then). June is a crapshoot, it can be nice and warm or surprisingly cold.

I guess Jan-Feb are definitely winter, Apr-May definitely spring, Jul-Aug definitely summer, and Oct-Nov definitely autumn. The rest are kind of transitional and their weather unpredictable. Of course, the climate change isn't helping things, either.

https://en.wikipedia.org/wiki/Season