0.132 mR/hr Radioative Fallout, 5/14/11 Saint Louis Missouri

Took this sample around 1pm,  after a 20 minute 6 mile round trip driving through a Seattle Style all day rainfall. The readings max at 0.132 mR/hr, or roughly 13 times background radiation. Given that it rained twice yesterday and has been raining all day today, I am a bit surprised that the contamination reading is so high.