In general, frangipani can be pruned in the winter when plants are dormant. Frangipani is a tropical plant and will suffer from cold damage in colder weather. It also does not like to have its leaves wet for long periods of time at any point during the year. So it is best to prune frangipani when temperatures stay above 55 degrees Fahrenheit or so throughout most of the day and night for several weeks before Thanksgiving. Pruning should take place early enough that there is no chance of frost killing your plantings before spring planting season begins…or you may lose them altogether!