May 2018 National Climate Report National Centers for Environmental Information (NCEI)

An analysis of national temperatures and precipitation each month, placing the data into a historical perspective

Atmospheric carbon dioxide and Earth's surface temperature (1880-2019)

Coldest April for the US in more than 20 years

Fifth National Climate Assessment

May 2022 National Climate Report National Centers for Environmental Information (NCEI)

Global and European temperatures

May 2018 National Climate Report National Centers for Environmental Information (NCEI)

May 2018 National Climate Report National Centers for Environmental Information (NCEI)

Continentality index (CI) defined as the annual monthly maximum minus

Climate change in the United States - Wikipedia