Keep an eye on hurricane and tropical depressions forming in the Atlantic. Other than that, the water should be very warm, and the weather hot, but pleasant in the shade.
While we did not sail from Galveston, we did a Western Oct 2011. It was nice. The weather was a little rainy, but not all day rainy. We're doing another western in Oct 2013 so we were not deterred
We also sailed in Oct 2011 - seas were too rough for Grand Cayman even with rerouting - also missed Cozumel - made it to Key West but left way before sunset. Castaway Cay was windy and cool - water was chilly. Even the pools and deck were closed a couple days. Servers told us the week before was even worse for Eastern Caribbean - half the crew was seasick too. It was nice to be on the Magic - and the crew did their best - but was not our favorite cruise. So be prepared for potential bad weather and rerouting in October!
We did a western for halloween a couple of years ago., no problem stopping at ports, the weather was mostly beautiful. The cancelled a lot of excursions on castaway cay in the morning due to high winds but opened them back up in the afternoon. We did have half of a sea day where it rained quite a bit.
GET UP TO A $1000 SHIPBOARD CREDIT AND AN EXCLUSIVE GIFT!
If you make your Disney Cruise Line reservation with Dreams Unlimited Travel you’ll receive these incredible shipboard credits to spend on your cruise!