here in Huntsville,AL --
yesterday= 44F/42F == 6am dry/wet
today = 28/27
typical -- any season
80%RH = 'low'
actually at the Meridianville AL airport, which is close to me
so, don't tell everyone to open their crawl vents to allow dry air to circulate!
do carefull evaluation for attic venting, & vapor barrier placement!