When the wind makes it difficult to reach fish with a normal cast, try sending your strong forward cast into the wind and presenting the fly on the back cast.
Cold is another weather-related problem that fly fishermen often face, no matter where they fish. While those on the North Atlantic coast endure the harshest conditions, even anglers in Florida sometimes cancel trips because of frigid mornings.
When it's cold, I've come to accept the biggest challenge to be remaining supple enough to cast after the frigid run across Long Island Sound in 30-degree weather. While running in the boat, I wear enough clothes so that I would sweat to death if I had to make a cast while still fully dressed. Insulated underwear is a must; fleece pants rather than blue jeans help, too, especially with foul-weather gear like a windbreaker. I wear a fleece neck gaiter pulled up over my face and a wind-block fleece hat with earflaps. Pull that hood over the whole thing and zip up the throat.
I can't stand to wear gloves when I cast. My answer is to warm my hands between fishing spots. I wear a good pair of winter-weight gloves, and I have at least another pair in reserve in case one gets wet. If I'm not casting I've got them on. I always wear short boots in the boat, and inside them I wear a pair of neoprene socks. Neoprene is warm even if wet, and in the boat, especially on cold days, your feet won't do much sweating anyway.
Perhaps the most important piece of equipment, though, is the big waterproof bag that I take with me so that I can de-layer before casting. By taking the extra time to add or subtract clothing as the moment dictates, I'm able to tolerate a lot more cold than most people are willing to fish in. And I've found that the fish don't necessarily mind those cold mornings.
Rain ruins a lot of fishing trips. Yet fishing in light or moderate rain can often be productive. With few exceptions, overcast days are better for fishing than bright ones, but fishing ceases to be fun when everything is soaked. Keep you flies in weatherproof plastic boxes. Keep your extra clothes in a waterproof duffel bag, and keep your extra tackle in a waterproof gear bag. In a pinch, a trash bag will work for this purpose; I always have a couple of extra ones stashed in my gear should I need a quick waterproof layer.
Many people keep foul-weather gear stashed on board, but not boots. Wet feet will make your trip miserable, no matter what kind of pants or jacket you're wearing. Stash a pair of rubber boots where you can get at them if needed. Driving rain makes it nearly impossible to see while running a boat at any speed. Even if you don't need glasses for your vision, a set of wraparound sunglasses or even plastic safety goggles are a great comfort and safety feature in an open boat during a fast run in the rain.
No matter what the condition, fishing first light is often required for success on a number of game-fish species, so I often find myself making the run out to the grounds in total darkness. To be ready for this important time, a little organization goes a long way. I often start with one outfit that has a black fly and either a floating or intermediate line to keep my presentation near the surface as I probe the shallows that I suspect are still h'rboring feeding bass. You'll benefit if this outfit is set up the night before with just the right fly, a new leader, clean fly line and a sharp hook.
Also, on several nighttime occasions, I've nearly stuck my thumb into the mouth of a bluefish thinking it was a bass. A small, waterproof, plastic flashlight held around your neck with a piece of heavy cord can be held in your teeth to look into a dark tackle bag or to help land a fish. The light can also be used to signal a boat that's running too close.
Another good idea, especially in marginal conditions, is an inflatable life vest. A few years back, I bought one of the CO2 ones that automatically inflate when immersed in water. If I hit a log and was thrown from the boat while running in the dark, or if I tripped from an unseen wave and went over the side in darkness, the light and the vest could save my life.
Gear preparation is the best way to avoid gear failure on the water. Everything becomes more difficult in the rain, the dark, or in high winds and rough water. Think ahead and have your gear ready for the task. Anticipate the fishing that you'll be doing and have rods pre-rigged with the flies and lines of choice. Start out with fresh knots and leaders, but have others ready to go in small plastic bags marked with a waterproof marker to indicate the length or pound test. Don't wait until you put on a new fly to crush the barb and sharpen the point. Flatten the barb and dress the point before you tie your flies.
And above all, don't lose faith. When the weather looks threatening, a one of my friends says, "the fish don't mind, they're already wet." He's right. A good angler learns to work with the wind, using it if he can, and working around it if he can't. There simply aren't enough days in the year for most of us to get out fishing. Rather than sitting out those marginal weather days, why not make the most of them. And as I've learned, some of them may hold the best fishing that you're likely to run across all season.