Where I live, it rains almost every day in the late afternoon during the summer. Add to that the fact that the temp is above 80 during all daylight hours and the humidity is about the same. That makes for tough running conditions.
What to do?
Run in the rain. Sure. As long as it's not lightning, there is no real reason not to run in the rain. It's really all about your attitude. Most of the runners in my coaching group learn very quickly that running in the rain is refreshing and exhilarating.
A few things to consider:
One, wear older shoes. I don't think getting running shoes wet is such a big deal, but some people think it breaks them down. Personally, I think about the fact that half the running world is running in minimalist shoes, anyway. How much damage can be done by getting shoes wet? I've never thought it adversely affected any of my shoes. However, do be careful to dry them out appropriately when you get home. I don't advise putting them in the dryer. No, the best thing is to stuff them with something absorbent. Newspaper works well. Then put them in a warm place. If it's sunny later in the day or the next day, that's an option. If it's still raining out, put them somewhere where there is plenty of air circulation.
Also, if you are likely to end up frequently running in the rain, make sure you have several pairs of shoes. You don't want to have to put on wet shoes. Let them dry out between use, even if they're likely to get wet again.
Two, wear a hat. Seriously, wearing a hat is critical because it keeps the rain water out of your eyes. I always keep a spare hat or two in my car just in case of rain.
Three, keep an change of clothes, a couple of towels, and an extra pair of shoes in the car. While running in the rain is exhilarating, driving home in wet clothes and shoes is not. It's not too good for the seats, either.
What about a rain slicker? That's a good idea, if it is one that's made for running and if it's cool out. Here in Florida, the rainy season is in the summer when it's always hot. A rain jacket of any kind would be too hot.
Four, if there is lightning, don't run, at least not outdoors, but don't give up, either. Thirty minutes later, even 20 minutes later, it might be safe to run.
The best thing about running in the rain is that you feel like a kid. If you let yourself go and enjoy it, you'll have some of your best runs at these times. And another benefit is the even greater feeling of accomplishment. Unfortunately, half of all runners, maybe three quarters, are fair weather runners. When you're running in the rain, sadly, you won't see many other runners. You'll realize you've discovered something they haven't. Running in the rain is its own special kind of wonderfully pleasant, invigorating adventure. The rain drops on your cheeks are Mother Nature's kisses.
You may want to read a blog post I wrote a while back while visiting my son in California. When I was there, it rained every day, so, not wanting to waste time sitting indoors, I went 'rain running' every day, a great way to while away a many delightful hours, and a time I'll always remember fondly. That post is here.