Researchers have found an association between the amount of precipitation and prevalence of autism in California, Oregon, and Washington State. The researchers do not blame the rain itself, but suggest that the association points to some aspect of the indoor environment as a trigger.
Autism Prevalence and Precipitation Rates in California, Oregon, and Washington Counties.
Michael Waldman, Sean Nicholson. Nodir Adilov and John Williams.
Arch Pediatr Adolesc Med. 2008;162(11):1026-1034.