I have a sliding glass door that is leaking due from snow melting off the upper deck. Can I apply caulk during the winter months will it hold until we can look at the deck above after the snow melts?

Thanks

Caulk and the material it bonds to both like to be above 50 degrees. If you must get a temporary fix put your caulk on a heat register for an hour and use a hair dryer or heat gun to warm up and dry the door rail. If the rail is aluminum it should not take too long.