Climatological Background  In June, the sun's maximum northward location is achieved at 23.6 degrees north. Surface heating of the continents has initiated summer monsoonal systems or northern hemisphere warm season rains. In the Southern Hemisphere winter is setting in with fewer daylight hours and cooler temperatures. The southern parts of South Africa, Australia and South America are now in the path of mid latitude storm tracks. 

Temperatures Over Land

Unusually warm conditions persist in drought-stricken southwest Asia while unseasonably high temperatures spread northward to central and northern Russia.

Europe:  After a brief respite in April, above average temperatures returned to central Europe.
Asia:  Temperatures were well above average across a broad region of central and southern Asia from Afghanistan and Pakistan in the south northward to central and northern Russia.
Africa:  Much of the Sahel in western Africa was unseasonably warm, temperatures were slightly above average across much of South Africa. 
Australia:  Temperatures were slightly lower than average across northern sections from Western Australia eastward to Queensland. 
North America:  Alaska and northwestern Canada saw an abrupt shift to cooler than average conditions in May.  Temperatures were well above average across eastern Canada as well as the western United States.
South America:  Unseasonably cool conditions developed across much of Paraguay during the month.

Precipitation

Irregular rainfall contributed to ongoing drought in the Korean peninsula and the re-emergence of unusually dry conditions in the North China Plain.  Pre-monsoon rains soaked sections of northern India while the onset of the rainy season in the Sahel of Africa was mixed.

Africa:  Rainfall was above average across southern Nigeria and the immediate Guinea coast while western and eastern sections of the Sahel saw below average rainfall.  In East Africa, May rainfall was mixed, with unusually dry conditions across sections of Kenya, southern Ethiopia as well as central Somalia and Tanzania.  Precipitation was near average elsewhere.
South America:  Below average rainfall fell across northeast Brazil while drought-affected areas to the south saw little relief with the rainy season coming to an end.  Coastal and central Colombia were also unseasonably dry for the month.  By contrast, western Argentina was unusually wet for May.
North America:  Unusually wet conditions prevailed across the upper Midwest of the United States while the east coast, Gulf coast and western US had below average rainfall.
Europe:  Unusually dry across central Europe.
Asia:  Precipitation was above average across central and eastern Turkey as well as western and far eastern Russia.  Below average rainfall continued over the Korean peninsula with irregular rains leading to moisture deficits over the North China Plain.  Pre-monsoon rains brought unusually wet conditions to sections of northern India and Thailand.
Australia and New Zealand:  Unusually dry conditions developed in eastern Australia including much of Queensland and New South Wales.  Deficient rainfall prolonged drought conditions in southern New Zealand while Tasmania was also unusually dry for the month.

Oceanic Conditions

Tropics:  Sea surface temperatures (SSTs) across much of  the eastern and central equatorial Pacific during May remained near their long-term average.  Slightly lower than average SSTs continued along the immediate western coast of South America while warmer than average SSTs persisted in the extreme western part of the basin. Overall, conditions currently indicate near-neutral ENSO conditions.   Most statistical and coupled models continue to predict near-average to slightly warmer than average SSTs in the eastern equatorial Pacific for the next 6 to 9 months.  Over the past few months some of the more closely watched models have also shown a tendency towards reducing the magnitude of the warming predicted for this time period.

Midlatitudes:  Above average temperatures persisted across much of the Indian Ocean.  Below average SSTs in the northern North Pacific strengthened somewhat during May as did the unusually warm water along its southern flank.  The central and western South Pacific remained unusually warm as did the subtropical regions of the North and South Atlantic.