The headline in the Arizona Daily Star read: “July sets record as hottest ever in US.” And, once again, the Star failed to get the rest of the story.
The AP story printed by the Star was based on a press release from the National Oceanic and Atmospheric Administration (NOAA) that read in part:
“The average temperature for the contiguous U.S. during July was 77.6°F, 3.3°F above the 20th century average, marking the hottest July and the hottest month on record for the nation. The previous warmest July for the nation was July 1936 when the average U.S. temperature was 77.4°F. The warm July temperatures contributed to a record-warm first seven months of the year and the warmest 12-month period the nation has experienced since record keeping began in 1895.”
Those temperature records were based on the old US historical climate network stations (USHCN) which are shown to be inaccurate due to siting problems, encroachment of urban areas, and poor instrumentation. (See my post: US Temperature trends show a spurious doubling due to NOAA station siting problems and post measurement adjustments says a new study)
But there is another, more modern, group of weather stations established by NOAA called the United States Climate Reference Network (USCRN). These are modern stations, sited well away from urban influence, that use state of the art instrumentation and are therefore not subject to the problems associated with the old USHCN network.
Those USCRN stations show the monthly average U.S.temperature for July 2012 was 75.51°F, some 2.1 F cooler than the touted results from the old USHCN stations, and 1.9°F cooler than July, 1936. See the full story details from Anthony Watts here. See also as Dr. Roy Spencer weighs in on this issue here.
For some perspective and contrast, while July in the U.S. was warm, it was not so in the U.K. When I was in the U.K. in June, it was colder and wetter than normal. That trend has continued into July with U.K. temperatures almost 2°F below the long-term average. (Source) The implication, of course, is that U.S. temperatures don’t necessarily reflect global conditions.