If you thought this April was cooler than usual, you live in either the eastern US or in the Middle East (I don’t). In most other parts of the world this April was warmer than usual and on land the warmest on record, including sea surface data the third warmest. The NCDC reports that:
Based on preliminary data, globally averaged combined land and sea surface temperature was the warmest on record for January-April year-to-date period and third warmest for April.
Global land surface temperature was warmest on record in April. Temperatures were above average in Europe, Alaska, western U.S., eastern Brazil, northwestern Africa, and most of Asia. Cooler-than-average conditions occurred in the Middle East Region and the eastern half of the contiguous U.S.
The large anomaly (5C or 9F) in Siberia is interesting. Also the sea ice extent is lowest for any April on record. Records began in 1979.
Look at the NCDC site for more information.