Q:

Does anyone know what the approximate Apollo cabin temperature and humidity was kept at? I am curious if the unusual 100% O2 atmosphere affected other aspects of the cabin air.

A:

From this NASA report:
https://history.nasa.gov/SP-368/s2ch5.htm

The design range for temperature and humidity control in the Apollo Command Module was 294° to 300°K (70° to 80°F) [i.e., 21 to 27 °C] with a relative humidity of 40 to 70 percent. Similarly, the design range for the Lunar Module was 291° to 300°K (65° to 80°F) [i.e., 18 to 27 °C] with a relative humidity of 40 to 70 percent.