I usually do 88 or 88.5 or. In the summer I go on the cooler side because my room gets warmer and temps can warm up in the bator at miday. Most bators only heat, not cool so you want to allow for increase if room temps go up.
I do have 1 incubator that does heat and cool called an ARTI, but that is for my dragon eggs which incubate at much cooler temps.