claim: The main reason behind this mid-century cooling was global dimming due to anthropogenic sulfate aerosol emissions.
evidence: The hottest officially recorded temperature was 103 °F (39 °C) on July 29, 2009; the coldest recorded temperature was 0 °F (−18 °C) on January 31, 1950; the record cold daily maximum is 16 °F (−9 °C) on January 14, 1950, while, conversely, the record warm daily minimum is 71 °F (22 °C) the day the official record high was set.