I believe a camera is nothing more than a tool. It is there to do a job and, within reason and with a little care, it should never become an obstacle to you in taking a photograph. I am fortunate that I now own a body that is weatherproof, but most of my lenses are not. I have used my equipment in rain, snow, mist, drizzle and bitterly cold conditions. Not once have I had a problem with anything, apart from the odd shutter release cable, but I do regard these as disposable, though, as they are so cheap on eBay that now I carry several.
Previously, I have owned several Canon camera bodies, none of which were regarded as weatherproof. I was shooting a lot more seascapes back then, so bodies were prone to getting the occasionally soaking, but generally speaking, I never encountered many problems so long as I was quick to wipe the moisture off, and didn't let the water pool around the buttons and dials. I have found that electronic equipment can handle a fair bit of rain, but what they don't like is to be kept in a damp environment. Stowing away your wet camera gear inside a damp bag after you’ve been soaked out in the field is asking for trouble, which without a doubt would be expensive.
I was never willing to let the inadequacies of my equipment dictate the kinds of shots that I could take. It felt limiting and harmful to my creative development and would have held me back as a photographer. I understand people’s reluctance to expose their cameras and lenses to the elements. They are expensive and precious pieces of gear. But, at the same time, they are there to be used, and if you can only take them out when the conditions are optimal, then you are being unreasonably restricted.
The moment you put your camera before a potential shot then maybe it’s time to rethink your process or the equipment that you have. Do you really need that expensive 40-megapixel body if you’re only ever going to view your pictures on the web? If not, buy something either second-hand, or more basic, and just get out there in all sorts of weather and shoot. The variety of conditions will transform your images and you'll probably get much more satisfaction from your photography.
You shouldn’t ever have to limit yourself to dry sunny day shooting, or indeed anyone set of conditions. This kind of photography, in my view, is pretty one-dimensional, will bring your photography into stagnation, and more than likely you’ll get bored. You need to shoot in all kinds of weather so as not to limit your view of the world and hinder your ability to grow and change, which is one of the great dangers of creative expression. You have to venture outdoors in all weather. Staying indoors because it seems like a bad day will only limit your photography. I will try and shoot in almost any conditions, so long as my personal safety is not at risk. Hail, sleet and snow, wind, mist and fog, bring it all on. As I’ve said a few times before, challenging yourself, being willing to make mistakes, and doing things differently from your usual; is the best and most consistent ways to build your skills and experience. Diverse weather conditions are an essential part of photography, and with a little care and maintenance, your equipment should be able to handle them.
Just remember, you stay in, you miss out !