Protecting your camera in bad weather When it comes to ugly weather on a hike, there are two major concerns: to protect yourself and protect your photo-gear. In short, all precautions to keep your body working apply to your photo-paraphernalia, i.e. stay reasonably warm and dry. Frantisek Staud

Cold
In cold weather the major issue is batteries, as they tend to die rather fast when the temperature drops, turning your auto-everything camera into an adornment around your neck or a useless load in a rucksack. Try to allow batteries to share your body temperature by keeping them in your shirt pocket or in a glove, and insert them into the camera only when needed. Also, always have a set of spare batteries somewhere close to your body - not in your backpack or camera bag. It is always helpful to switch off energy-consuming autofocus unless absolutely necessary.
In the most unmerciful conditions, battery independent manual cameras such as Nikon FM2 are the best choice.

Another potentially annoying problem in cold is moisture condensation. This becomes especially oppressive when entering a warm room from subfreezing outdoor temperatures (not the other way round). The condensation will fog your lens right-down, giving it an appearance (and usefulness) of a sweating empty lager can.
To prevent it, try the following: while still outside, put your camera into a plastic bag. Now, the moisture will condense on the bag and leave your treasure unaffected. If you do not have a plastic bag at hand, let your camera warm up slowly. Put it in a tightly sealed camera bag or leave it on a windowsill or in an unheated room until it gets used to the indoor temperature.

Yet another problem plaguing outdoor photographers in cold is static electricity. When advancing or rewinding a film in a low humidity area, and cold weather always means low humidity, you may build up sufficient amount of static electricity to spark within your camera body and leave lighting strikes on film. Not often, but it does happen. So if you are not planning to pride on enigmatic UFO streaks in your pictures, advance and rewind the film slowly. With automatic bodies, shoot only one frame at a time and pray when rewinding the film.

Rain
Rain should not discourage you from taking pictures; it can give an unexpected dimension to an image. Unless you are out with a disposable camera, protecting your photo-gear against water may become a problem. Set up your tripod, cover your camera and lens with a plastic bag, shower cap or even spare gaiter, decide on composition and exposure and when the time comes uncover just the front of the lens to take the picture. A lens hood or a UV filter may help you protect the lens' front element. Cord release makes pressing the shutter a lot easier in these situations.