A weak front will pass through central Indiana later tonight. The front will likely stall out south of Indianapolis Thursday morning. Behind the front, slightly drier air will move in. This will allow for it to feel more comfortable (less humidity), but it will also allow temperatures to quickly rise where there is sunshine. Temperatures will likely be warmer north and northwest of Indianapolis Thursday - highs in the lower 80°s.
I think you'll notice more of a difference in the humidity Friday. Computer models suggest dew points will be in the middle 50°s. That is much more comfortable than what we had Wednesday with dew points in the upper 60°s.
South of the cold front, showers and a few thunderstorms will be possible Thursday afternoon. This will likely be south of a line from Bloomington to Columbus.
Our next decent shot of rain should be Saturday. All computer models suggest showers and thunderstorms to start the weekend. The best day of the upcoming weekend should be Sunday when it will be much less humid.