Does humidity effect the epoxy curing process?

It depends on the type of epoxy being used.

For UltraClear table top epoxy:

Humidity is not an issue. The epoxy will cure properly if the temperature is kept at or above 75°F; warmer is better. Some thermostats are not accurate, so it's always better to set the temperature a few degrees higher than 75°F to ensure that it cures correctly.

For UltraClear deep pour epoxy:
You will want the humidity to be 50% or lower when using deep pour epoxy to have a clear, transparent finish.