"May 22, 2022. Low 37 deg. Thought we dodged the bullet. We replanted about 1/2 our beans in the next 7 days. Every terrace channel, low spots in fields, ground on the east side of acreages, etc. Evidently cold air settling in is colder than the air measured at weather stations."  
 This and i would bet the wind was calm, preventing mixing of air.