Here are a couple of tremendously useful websites for planning your kayaking trip. When deciding whether you should do your trip, you need to consider the wind conditions, and what they are likely to do. If the wind is below 10 mph, then it should be a good day paddling. But if the pressure (barometer) is decreasing, then a storm might be coming in, so look carefully at the forecast. Wind conditions are usually calmest very early in the morning, with wind speed increasing throughout the day. Once you've decided it is time to go out, you now need to decide how to dress. Dress for the water temperature. This can be tricky to figure out, but I found a website with a great marine forecast. If you have your own resources, perhaps better or also useful, please share them in the comments. While you are out on the water, you can monitor weather conditions on the VHF weather band.
iWindsurf.com is a website for windsurfers, but they maintain wind meters in many locations and offer free memberships. You can monitor the real time wind speed of your destination before you go. Any weather website will give you the winds for the nearest city or town to your put in, but iWindsurf measures the wind at the water, so it is much more useful. Always check the barometer and if it is dropping, then a storm may be coming in.
I found water temperatures hard to find until I found the Weather Underground. Search for a large city near your put in if the small town closest isn't available. Look for the marine forecast link. This will tell you the water temperature if available. If you can't find the water temp for your exact area, look for some readings around your area, and guesstimate. The idea is to be prepared to perform a self rescue in water of that temperature. The amount of time a person can survive in cold water depends on a number of factors, so don't trust any published tables (one of which I link to in an earlier post). It depends on your body fat, how accustomed you are to cold water, how you react to shock, your mental state of mind, your swimming ability, and many other factors. I personally wear a farmer john wetsuit whenever the water is below 60, even in hot weather. You can peel it down to your waist if you want, then put your PFD back on. But this means you'll have to perform your self rescue with a cold upper body. Only zip the wetsuit back up if you can do so safely. Consider that if you capsized, the conditions that caused you to flip might make it unsafe for you to take off your PFD to zip your wetsuit back up. I always paddle with my wetsuit zipped up, and with my PFD on snugly.