As weather disasters dollar figures are directly correlated with housing, CPI isn't even close to a proper adjustment. CPI says the house my mom bought in 1994 for $114,000 should be $239,000 today. It's worth about $1.2M...
That's dominated by the scarcity value of the land, not the value of the labor required to repair or replace the building on it. The "inflation" we should worry about here is contractor salaries and the cost of building materials. CPI seems fair to me.
No inflation metric is going to be perfect here, but CPI seems not unreasonable to me: disaster cost factor includes rebuilding costs, i.e. materials and labor pricing, not speculative real estate value.
In other words: the "real" cost is probably somewhere between the CPI-adjusted figure and the inflation-adjusted real estate speculative gains. But either way, the trendline is the same.
