h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

If anyone knows, how do things like El Ni~no effect this?

El nino affects climate rather than seasons. It may be a matter of definition, but both things are different nevertheless.

Arn't the seasons defined by climate, aside from the areas about the poles and equator of course?

I think seasons are a very abstract concept. They are simply parts of the year. For astronomers, north-winter begins on 21st December, for meteorologists on 1st December. On these days starts the south-summer, too. That's it.

Of course the global *climate* was indeed affected by El Nino. However in a very complex way. It could be predicted partly because El Nino is a periodical phenomenon and there are statistics. But *the* El Nino was very strong, so by and large you can only see afterwards what has happened. And it is extremely dangerous to make El Nino responsible for a certain whether phenomenon.

Meteorology isn't an exact science yet.

"aren't seasons defined by climate"

I'd guess that its more the other way round. Climate is partially determined by seasons, along with other variables, the only of which I can think of is altitude, but I'm sure there are others.

I'd go along with seasons being determined by climate. Many parts of the world, for example, have only three seasons - hot, cold and rainy.