Yeah when the weather is hot and humid like we're all seeing it's a dread having to go out to do anything, much less any yard work. The bad thing is if you go out too early before the dew has evaporated it's doubly bad on mowers, blades & decks and it doesn't do the grass any good either.
It was almost this bad yesterday when I trimmed the front yard only at mid morning and mowed most of our place mid to late afternoon but I didn't finish due to the conditions. That's for another day.