Of course even I'm guilty of waiting until that rainy day to change mine. It's certainly no fun to have to stand in the rain to do this, but it's important that you can see clearly through your windshield. To avoid an accident you need to be able to see and react in time.
In this video I'll show you how easy it is to replace them yourself and save you money. Make sure that you ask for help if you are buying them from an auto store. Many times the driver's side wiper is longer than the passenger side. You can look this up in the wiper guide book in the wiper section or ask them to look it up for you on the computer. Some stores will even offer to put them on for free!
Don't compromise your vision of the road, check your wiper blades and replace them before it rains.