Those with allergic rhinitis or pollen allergies may welcome rain, but for those with mold allergies, rain may bring in more problems. Just as allergists are seeing the last batch of those with hay fever, those with problems with molds are also starting to pour in.

"Actually I expect it to get worse over the next few days because we've had the rain for a few days and it takes a little while for the mold to start growing and producing spores," he says.

Warm, humid weather is conducive to mold growth. Check your home, especially where it's always wet and there's no ample ventilation such as the kitchen and bath. It can be especially important for preventing multiple allergies later on. If you have to work outdoors for long periods, tending your garden or raking the yard, for example, better wear a protective mask.