Thanks for the info. I think the link is a dot info not a dot com: https://seatemperature.info
P.S. My two cents; I teach up to Skills L-2 at Jericho Beach Kayak and I generally wear my dry suit year round with merino wool base layers (top and bottom), wool socks, synthetic t-shirt, nylon pants and neoprene gloves. This works for immersion in winter and summer. If I get cold in the winter I’ll add a thin jacket. In summer I spend a lot of time in the water, either standing up to my waist or chest teaching rolling, rolling myself for practice or to cool off, and demonstrating solo re-entries. On really hot days I’ll go with a “farmer john” wet suit. I always keep a neoprene beanie in my pfd. You can put one on cold and wet and within 5-10 seconds your head will be warm. Goes a long way for comfort in cold conditions and can help prevent hypothermia.
Long story short, my motto is dress for the water first and weather second. Always look up water temperature as part of your trip planning. Always carry a complete change of clothes and bivy sack in a dry bag on all outings.