The air temperature should be between 50 degrees and 85 degrees F. The dew point temperature should be five or more degrees lower than the ambient air. Avoid painting in the sun, too (the sun-warmed surface can be ten to twenty degrees higher than the ambient air). Also, don’t stain if it’s windy — the stain will dry too fast.
Try to plan your work so that you are always painting in the shade. Stop at least two hours before sunset (due to the danger of condensation).