The 120° Rule.
Spring paddling is a wonderful thing, but there is also a certain element of danger in the cold water temperatures.
A good rule of thumb to follow is the "120° rule."
This means you should wear a wetsuit or drysuit whenever the sum of the air temperature
and water temperature is equal to or less than 120°F. Warm weather does not cancel out the danger of cold water, wearing lighter clothing on a warm day increases risk. No matter how nice and sunny it may be, do NOT go paddling unless you are wearing the appropriate clothing, and of course, a PFD. If your body is unprotected, meaning you have inadequate clothing on, you will have:
1 minute- when you suddenly end up in the drink, cold shock can make you hyperventilate for about a minute. Having a good PFD on is imperative, keep your airway clear of water and wait for your breath to come under control.
10 minutes- You will have about ten minutes of useful dexterity. Take advantage of this and get yourself back in your boat. Have you practiced your rescues?
1 hour-You will have about one hour of useful consciousness. If you can't get back in your boat, secure yourself to it so that your airway will stay clear.
Protect yourself, increase your comfort, and potentially save your life with a quality dry suit.