We just got back last night. We had to deal with rain for three days. Only one all day. We used our Coleman rain jackets for two of the days and then the .88 poncho's from WalMart for two days. The ones from Wal Mart are longer than the others. We use them one day and toss them. We had a couple in our bags at all times, so that if it really got wet, we could toss that one and use another. If it's not raining for a long period, you can shake them out, fold them inside out, hang them to dry in the room and use them again. They take up almost no room.
I do recommend that if continual rain is expected when you go, to make sure and pick up a rain jacket. It will keep you and any bags/backpacks dry. Our's zip up so they are very easy to get on and off. An umbrella is a waste and hard to carry. I also recommend a cap/hat to wear over or instead of your hood on the poncho or rain jacket as it keeps the rain out of your face and those hoods can get hot. We went during a hurricane last June, so we actually wore the pants that came with the jacket. We were able to stay dry and ride all day while others left and went back to their resorts. That was good for us, bad for them. A shower is one thing, but this was a hurricane.