Look at the USGCRP Climate Science Special Assessment: Volume 1: Chapter 6: Temperature Changes in the United States https://science2017.globalchange.gov/chapte

Look at the USGCRP Climate Science Special Assessment: Volume 1: Chapter 6: Temperature Changes in the United States https://science2017.globalchange.gov/chapter/6/ https://science2017.globalchange.gov/chapter/6/ Scroll down to figure 6.3. You can see that the 1920's to 1940's had more extreme heat events than any time since. Figure 6.4 is also useful to look at.