In March, high temperatures over two-thirds of the continental US set numerous records and made it the nations warmest March on record. April has been no slouch either, as high temperature records have continued to fall. But at the time of our last report, the services that track global temperatures hadnt analyzed the global extent of the warmth. Now that the numbers for March and April are available, its clear that the rest of the globe generally hasnt shared the USs record heat.
Globally, the current period of warming began back in the 1970s. NASAs GISTEMP tracks the current global temperature against a baseline established by the 1951-1980 average, and it hasnt seen a calendar year below that average since 1976, or a month below it since 1994. The US climate has generally reflected that, with high temperature extremes dominating over the last several decades, as shown below.
SOURCE: Record-setting 2012 warmth largely confined to North America, western Europe | Ars Technica.