evidence: CLAIM: The U.S. National Climate Assessment found that U.S. heat waves have already 'become more frequent and intense,' that the U.S. is shattering high temperature records far more frequently than it is shattering low temperature records (just as you’d expect), and that it is seeing correspondingly fewer cold spells. [...] This is true and is also consistent with findings from other areas of the world. For example, Dr Sophie Lewis led work* that showed in Australia there have been 12 times as many hot records compared to cold records since 2000. - Lewis and King (2015) Dramatically increased rate of observed hot record breaking in recent Australian temperatures, Geophysical Research Letters