Watch the Rocks
Any rocky terrain immediately becomes more dangerous and precarious during—and immediately following—the rain. Wet rocks become hazardously slick or loose, and mosses and grasses add to the danger. If you have to hike on steep, rocky inclines, ask yourself if it's worth the risk; it might be wiser to camp for the night and wait to hike when everything dries.
At the very least, minimize your chances for injury by wearing closed-toe shoes with ample ankle support and grip surface on the soles. Hiking sticks aren't a bad idea either. And make sure all the weight is evenly distributed in your pack to aid in your balance and traction.
More: How to Pick the Right Hiking Shoes
Be Smart About Lightning
Lightning usually ranks alongside drowning as one of nature's preeminent killers. Lightning can actually strike before, during and after the main thunder clouds have passed overhead. If you're swimming or in a boat, get out of the water immediately. If you're on land, find a spot that's not on or near the highest geographical point.
Additionally, don't hunker down beneath large branches that could break and fall during a storm (Outdoorsmen call such branches "widow-makers" for a reason). Keep in mind that storms can be extremely frightening for children, so if you're camping with kids, plan ahead with topics that will keep your kids calm during dangerous weather.
More: Lightning Safety for Hikers
Air Out Your Wet Stuff
If you've endured a storm during your trip, you likely packed up your gear while it was still a little wet. From clothing to shoes to tents, it's important that you unpack this stuff immediately following the trip to let it fully dry. Otherwise, molds, mildew and other mysterious scents will develop and ruin all of the fabric, and rust will corrode metal items like tent parts, saws and utensils.
More: Gear up for Camping Season
Try these rainproof techniques out at a spring campsite