Malcolm Hoar wrote:

Of course, you're welcome to toss your wet, mud-covered,
fully-fueled mower in the garage. I doubt it will explode.
But the chances are it won't start (easily) next spring
either!

I'm curious, what are you doing that is causing your lawn mower to
become wet and covered with mud? When I mow the lawn, the grass is dry
and there is no mud.

I put the lawn mower in the shed from November until April, just
cleaning off whatever old grass is stuck to the deck and the blade. In
April I check the oil, top off the fuel tank, and it starts just fine.
You wouldn't want to leave gasoline in the tank for a year without
adding some STA-BIL, but six months is just fine.