Winter in EU2 is a status that some provinces have, which dramatically increases supply attrition. The effect in land provinces is simply called "winter"; northern sea zones also get a wintry effect, ice.
When a land province is in winter, it is depicted in white on the main map. There are only two effects of winter, both of which are part of the computation of land attrition:
- The actual supply level in a winter province is reduced dramatically. The amount is -10 in an owned province (regardless of control), or -25 (!) in an unowned province, again regardless of control.
- The maximum attrition level is increased by 10.
Winter is tied to climate. There are at least three different climate zones which get winter. In the far north, winter can go from October to April. There are relatively few of these provinces. Most more northern provinces can get winter from November through to March. Finally, there are a few provinces in the southern hemisphere which get winter, which happens from May through August.
Sea zones in the same time frames may be depicted with little icebergs in them; this effect, called ice, dramatically increases naval attrition.