Here's some bad science

The study concluded the following -

'These results are consistent with the existence of an environmental trigger for autism among genetically vulnerable children that is positively associated with precipitation. Further studies focused on establishing whether such a trigger exists and identifying the specific trigger are warranted.'

Autism Prevalence and Precipitation Rates in California, Oregon, and Washington Counties

Michael Waldman, PhD; Sean Nicholson, PhD; Nodir Adilov, PhD; John Williams, MD, MBA

Arch Pediatr Adolesc Med. 2008;162(11):1026-1034.