Personal Injury - a recent study found that even a light drizzle increases the chance of a severe auto crash by 27%. The first ten minutes of rain are the most dangerous as dried oils on the road surface become activated by moisture. Once a skid begins, the greatest risk comes from an "overcorrection" of the steering wheel, sending the car across a roadway opposite from its original skid direction. Keep a close eye out for poor or inexperienced drivers whenever rain starts - especially after a particularly dry period.
Bankruptcy - most standard insurance policies do not cover flood damage to a residence. Special flood insurance must be purchased. Beware. Even backed up sewers aren't covered on most policies (unless you pay extra for the coverage). The average residential flood damage amount is $30,000, obviously depending on degree of flooding, and extent of items damaged. Many flood insurance policies can be acquired for $50-$60/month.