I’d have to agree with Logan here, the baggy long trousers with boots looks more winters as it’s more layers and such and so going with swimming trunks or something else could help.

As a little stylising tip, keep in mind this is strictly from a suggestive standpoint, I’m not saying this should be added. Adding outlines and then for where the body and the clothing meet, add a little few gradients that fade to one solid colour so there’s a cutoff presenting the clothing and body a bit more separately.