I recall reading that epoxy and urethane paints will eventually cure/set at as low as 50 degrees F; however, the lower the temperature, the slower the set; and, the slower the set, the more chance of dust, etc settling-on and setting-in the paint.
I think you will find that a manufacturer will recommend 70 degrees F and low humidity for best results. They will most likely not give a low temperature limit for guaranteed "acceptable" results. The same would be true for acceptable higher temperatures - if the paint sets too fast, multiple coats might not adhere properly (however, perhaps a higher temperature reducer could be used).
Where is MARTINSR? He'd have a good answer, from a pro.
