Cooler weather this spring, followed by high precipitation and the current warming trend could mean that mosquitoes that carry the West Nile virus could be in higher numbers than last year, Moore says. Cool weather kept the mosquito population low last year.

"A spring with lots of snow and rainfall followed by warm weather tends to be a sign that these mosquitoes will be in higher numbers because the weather pattern provides them with more habitat," Moore explains. "Warm weather leads to runoff and flooding, which leaves standing water for mosquitoes to lay their eggs."

Moore's research group hasn't found any mosquitoes with the virus so far this year, but the group will continue to test.