From Ole Humlum, Professor of Physical Geography, Department of Physical Geography, Institute of Geosciences, University of Oslo, Norway.
Ole Humlum´in nettisivu
"Please see here (PDF) a site with meteorological information updated to August 2009. All temperatures are shown in degrees Celsius. In the maps showing the geographical pattern of temperatures, the period 1998-2006 is used as reference period. The reason for comparing with this recent period instead of the official WMO 'normal' period 1961-1990, is that the latter period is affected by the relatively cold period 1945-1980. Almost any comparison with such a low average value will therefore appear as high or warm, and it will be difficult to decide if modern surface air temperatures are increasing or decreasing. Comparing with a more recent period overcomes this problem.
In the other diagrams the thin line represents the monthly global average value, and the thick line indicate a simple running average, in most cases a 37-month average. The year 1979 has been chosen as starting point in several of the diagrams, as this roughly corresponds to both the beginning of satellite observations and the onset of the late 20th century warming period. Surface air temperatures August 2009 was generally low at northern mid latitudes. Also southern Africa experienced relatively low temperatures this month. In contrast, equatorial Pacific Ocean, northern Argentina and Australia were relatively warm.
In the Arctic, most of the Arctic had temperatures near or below the 1998-2006 average. Only northern Canada and parts of Greenland were relatively warm. In the Antarctic, most of the eastern part of the continent was relatively cold in August 2009, while parts of the peninsula and the region around the Ross Sea and ajoining land areas were relatively warm"