I have installed wooden cabinets in prob 2 dozen garages in Florida (both my own and other peoples) from S. Fla to N. Florida, with zero problems with heat and/or humidity.
Granted they were quality wooden cabinets (my fav is to buy good quality kitchen cabinets that people are selling when they remodel a kitchen and convert them) ... but it not that hot or humid here and it if it rains in your garage .... cabinets there are the least of your problems.
