“Every single metric shows that summer maximum temperatures are cooling in the US,” says Tony Heller. “Heatwaves are becoming shorter, less intense and covering a smaller area.”
We need to know the truth on this, because summer temperatures can greatly affect crop production. It took only two years of crop failures to bring on the Great Famine of 1315-17.
See entire article, along with more graphs:
https://realclimatescience.com/2017/07/us-summers-are-getting-much-cooler-2/