0am:The Oak Island, NC forecast for Mar 15 is 46 degrees and Overcast. There is 47 percentage chance of rain and 20 mph winds from the Northwest. 3am:The Oak Island, NC forecast for Mar 15 is 40 degrees and Clear. There is 47 percentage chance of rain and 20 mph winds from the Northwest. 6am:The Oak Island, NC forecast for Mar 15 is 35 degrees and Clear. There is 49 percentage chance of rain and 18 mph winds from the Northwest.