Jacksonville Weather 2025. For the first three months of 2025. January is jacksonville's coldest month, registering average high temperatures of 63.1°f (17.3°c) and lows of 47.8°f.

The climate in jacksonville during may can be summarized as hot, humid and a little damp. January is jacksonville’s coldest month, registering average high temperatures of 63.1°f (17.3°c) and lows of 47.8°f.