The El-Nino associated warm sea surface temperature anomalies persist across the equatorial Pacific Ocean. Meanwhile, the weather in the Northern hemisphere extratropics is still dominated by the strongly negative phase of the Arctic Oscillation, with the seasonal mean wintertime Arctic Oscillation index being likely to become the lowest on the record since 1950

During the period from December 2009 through the first half of February 2010, the signals associated with the negative Arctic Oscillation polarity were observed over most of the Eurasia. Particularly, anomalously cold was in Europe, most of the Russia, Mongolia, northern and eastern China, and Korea; while warm anomalies prevailed in Southern Asia, southern and western China, and Indochina.

Cold signals were also found in the northeastern Australia, part of Canada, USA, Mexico, and the southern tip of South America. On the other hand, warm and dry conditions were observed in Africa, west and south parts of Australia, and northern and central South America. Western Canada, Greenland and most of the central Arctic also experienced warmer-than-normal conditions.

There have been drier than normal conditions over the northern part of Africa and Central America as well as much wetter than normal in the Mediterranean and Florida key region during the period from December till the first half of February. In other regions, precipitation conditions were varying. Dry conditions over Maritime Continent and the adjoining northern Australia in December were replaced by wetter-than-normal conditions in January and came back to dry conditions towards the end of the period.