No abstract

The persistence of high values of relative humidity for several hours to a few days has wide-ranging implications for natural and human systems. Among its many impacts, persistent high relative humidity contributes to reduced atmospheric visibility, fog frequency and duration, road and powerline icing, the occurrence of foliar plant disease and the temperature at which heat-related morbidity and mortality can occur. Despite this, the characteristics of humidity spells-including shifts with climate change-are rarely investigated and consequently poorly understood. Hourly relative humidity, precipitation and temperature for 35 locations in the Lower Peninsula (LP) of Michigan during 2003-2017, and for seven locations during 1973-2017, were used to assess, by biweekly periods, spatial, intra-annual and inter-annual variations in the char