[jbrown1984]

How late is too late in the season to do a split? This is my first year and want to increase my hives but don't want to set the "new" colony up for a tougher winter than necessary. I live in Kansas.

 

[GregV]

How late is too late in the season to do a split? This is my first year and want to increase my hives but don't want to set the "new" colony up for a tougher winter than necessary. I live in Kansas.

Not too late.
However, depending on your local flow pattern, may need to feed so the splits can grow.
Some places are entering/entered the summer dearth already (like maybe Kansas, depending on the exact location).