Beginning of Fall Message

frost

Scattered frost has now been observed in some areas of the Commonwealth, but not enough yet to end the mosquito season. Please be aware that risk from mosquito-borne diseases will be present until we receive a hard frost and freezing temperatures predominates throughout the region.

October 18, 2018

A light frost occurs when the nighttime temperature drops to below 32 degrees Fahrenheit (0°C), and refers to the conditions that allow a layer of ice crystals to form when water vapor condenses and freezes without first becoming dew.

A hard freeze (or hard frost) is a period of at least four consecutive hours of air temperatures that are below 25 degrees Fahrenheit (-4°C). Many plants (and mosquitoes) can survive a brief frost, but very few can survive a hard freeze (from https://www.almanac.com/blog/almanac/musings/how-predict-frost)