But you're not likely to see any lines at the polls.
Rice University political scientist Bob Stein says there were only about 20,000 early and mail-in votes cast, and election day won't be much better.
"I don't think we'll have over 50,000 votes now, total cast, and that would be a lot. I'm looking at probably 6-7 percent turn-out, which would put it into the 35,000-40,000 vote range."
Stein says Saturday run-offs usually draw less interest than Tuesday run-offs. In fact, the city is considering switching all run-off elections to Tuesday. He says in general, voter apathy is a big problem in this run-off.
"Run-off elections for races that are single-member districts have never generated anything but very, very low turnout because not only are voters not paying attention to it, but the candidates are not doing much to turn them out, and we started off with less than 20-percent of the voters showing up in the general election and that was with some interesting ballot initiatives, so it's no surprise, and if it rains on Saturday, that will only depress the vote even more."
Houston Matters discusses the run-off election