Being a grass type comes with some convenient little upsides, like being a bit more resistant to hot summers than most other types, not including ones like ice or fire that can provide their own cooler temperatures or are practically immune to the heat that is.
If anything, sunny summer days are maybe a little too enjoyable for them, provided there's water involved too, like some light rain or in this case, a convenient sprinkler running, as Slethy here can attest to, once he wakes up from this extremely pleasant nap anyways~
He's absolutely going to be a bit embarrassed about it when he does though, and probably return later with an apology and an offering of some freshly baked goodies.