Have Cruised many times during this time frame and luckily have had great weather. If going out of Port Canaveral, expect high 60's to low 70s, Miami usually mid 70s. We have also Cruised out of New Orleans this time of year and temps in the 60's then by 1st sea day approaching 80.
We drive to the ports so we always head down at least one day earlier, but have left an extra day earlier to beat weather.