The biggest problem is that the lawn under the mower won't be watered by rain........
Hope you have that kind of $ cause it will ruin it..............Get that Big Family to help you push it under the shed.
Silly me, when i read the Q i thought the 'lawn mower' was like a guy doing the mowing outside. Yeah i know, i didn't grow up in the suburbs....LOL
It will melt in the rain, and you'll never have that recipe again. Old folks will understand this.
What!!! no you cannot leave your mower in the rain! it will go rusty and the rain will ruin it!!!