Radioactive Rain in Saint Louis Missouri on May 5th 2011
The readings averaged 7-10 times normal background readings, 0.103 mR/hr maximum.
The readings were taken from two the hoods of two separate vehicles. Both had been in different parts of the city and in the rain for roughly the 1.5 hours. The first had been driven approximately 4-6 miles round trip through the rain; the second vehicle had been stationary.
The highest reading on the driven vehicle was 0.103 mR/hr; the highest reading on the parked vehicle was 0.075 mR/hr. Given how close the values are to each other, it is unclear if the differences are a result of the driving or just natural fallout variation from one part of the storm to another.
To date, the maximum fallout reading I have recorded in the Saint Louis area was 62x background radiation, 0.686 mR/hr on 4/15/11