Rain wear became more important to me after getting soaking wet one too many times during my travels.
It is no fun going around with wet shoes. If you know it is going to rain and it is a warm climate you could probably wear flip flops, that's what I usually do. On certain trips, you are expecting rain or mud so you can take a proper boot with you.
Sometimes the rain puddles can be so deep you could ruin an expensive pair of shoes.
When you are dressed for the evening in the city, caught in a downpour, it would be nice to have some plastic bags in your purse and, a shoe lace or something to hold them on over your shoes.
There is a kind of plastic boot that you can put over your shoes.
Sometimes it's good to pack a muck shoe or boot.
I had a few trips where I did take an umbrella and a trench coat but of course you must remember to carry them with you to have them handy when needed.
I got drenched in downpours. Once on the way from the bus stop in Rome when I was going to the Vatican museum. I never believed that I could get so wet so fast. It was like the sky opened up and put a waterfall above me. My feet got wet also as the sidewalks and roads were like rivers.
I always thought that the waterproof-poncho that can be carried in your purse were so ugly, but when I saw tourists putting them on, I really wished that I had one.
This past New Year in Puerto Vallarta was similar. We hardly ever get rain at that time of year. It really came down. In the old section of town, water was over our ankles...we got very wet. I will be prepared in the future.
Yes, we lived through it and get to laugh about it now but it is not very pleasant and it bothers some people more than others.
I find Travel Smith a good place to find great looking rain wear.