The map shows where average surface temperatures were up to 7 degrees Celsius above (red), below (blue), or near (white) the long-term average (1971-2000) for the first half of 2010. The warming influence of an El Niño event in the tropical Pacific contributed to one of the two warmest January-June periods on record. The contrast between warmth in Canada and cool conditions across the North Atlantic is the influence of a strongly negative phase of the Arctic Oscillation.
The map shows difference from average temperature for July-December 2010. Temperature anomalies are more muted as the influence of the Arctic Oscillation fades across high northern latitudes. Meanwhile shades of blue in the tropical Pacific indicate the emergence of a moderate-to-strong La Niña in the second half of the year. Theheatwave in western Russia also left its mark on the July–December average temperatures.