I seriously doubt you will be doing much swimming this weekend. Forecast is that you are more likley to get white than wet.
Still, this is a very good time of year to visit the island - For a start, there won't be any midgies.
Depends what part of the Island you are heading for & where you intend to stay?
Personally, Elgol is a favourite but if you want to go walking, Glenbrittle is probably your best bet as you can get into the heart of the Black Cullin pretty easilly, which is spectacular.
Don't take it higher than the main corries if you are unprepared/inexperienced tho. The walk-in may be steep but easy but the mountains themselves are deceptively hard & the gabro is a harsh abrasive rock.
Up in the north, Uig is a good base, with a decent little cheap campsite (also virtually midge-free in summer) & a number of good pubs within a short stagger. Also a decent greasy-spoon for breakfast at the ferry terminal.
Nearby is the Fairy Glen & the spectacular Quirrang range is a short & interesting drive over the hill.
Dunvegan area is also good but a bit more remote.