I second Rovers90!
Tofino weather can be unpredictable and can change in the blink of an eye.
Always best to bring warm and waterproof clothing options just to be prepared.
It does happen that Tofino can be blanketed by fog during the better part of the morning, usually to lift by early-mid afternoon.
Generally Tofino is cooler than other parts of the island (ie. east coast) but it does have it's share fair of warm sunny days. Definitely bring t-shirts, long sleeves, long pair of pants, shorts, a light rain coat and a fleece jacket (for evening walks on the beach!).