The way I offer refunds is on a scale depending on how long the downtime was and the refund would be a % of their cost.
Most times I don't offer 100% refund, unless the downtime was for a prolonged period of time.
I don't mind people asking for refunds, but they also have to understand that in some circumstances, it is out of your control, sometimes, an act of god, like yours might have been since you are in Florida.
You are likely to still have your full costs to pay up as it wasn't the fault of the DC, therefore, I think anyway (And I wouldn't mind if this happened to me as a customer), since it also wasn't your fault, you shouldn't have to fully refund your customers.
If you want to try make them feel better regardless of this, how about working out what your profit is, then you can split that in refunds between customers, meaning your costs are still taken care of but you just won't be making a profit.
Obviously you will need to think about it a lot more if all your servers went down and it is your main source of income, not making any profit in that case could really hurt you and the business in the short and long term.
You could try telling your customers that it was totally out of your control, but they can have a partial refund if they like, then you can give refunds to those that request it.
I don't think many would really want a refund when it is as act of god like Florida had, I know I wouldn't expect anyone to give me a refund when something like that happened.