score:4
You will have to read your policy to know for sure.
There is some information here about how trip insurance policies usually handle natural disasters. In particular, it is relevant whether or not the disaster already existed at the time you bought the insurance. For hurricanes, they suggest the relevant date is when the storm is named; for Irma that appears to have been August 30, so if you bought the insurance after that date, you might not be covered.
Again, it is entirely possible that your particular policy has different terms. You have to read it.