[return to the red]

as long as the ground is thawed you can aerate...interesting thing about aerating your lawn though, unless you have a lot of thatch or soil compaction you don't need to aerate.

casual foot traffic on a lawn won't compact your soil enough that you need to do it yearly, this is all dependent on some other factors as well of course though

1 other quick hint too, if you are thinking about getting ahead of the game and fertilizing be aware that it will be wasted if the soil temp isn't above 4 degrees