Removing gratuitious cross-posting...
Lager yeasts perform best at lower refrigerated temperatures. Lagers
> in the above mentioned countries were mainly produced during winter
> months which aided in getting that nice lager flavor. Ales yeasts can
> ferment at higher temperatures and are typically done throughout the > warmer months.
Just for point of reference, the Germans and Austrians were doing cold-weather (and cold-temperature) brewing long before the advent of the lager yeast. The yeast was more of a response to existing brewing methods than the other way around.
Of course, once refrigeration came along only 50 years or so after lager yeast was discovered, they could brew year-round. But they were pretty much doing that anyway, from what I understand.
Anyway, I'm not sure if you were going for the historical reference or for homebrewing practice or for something else in your statement, but both types of brewing can be and are performed the whole year, and have been for quite some time.
-Steve