The NASA GISTEMP March numbers are out. You can pretty clearly see the drop in temperatures as a result of the collapse of El Niño. They’ve also changed the way they’re calculating the adjustments for time-of-day bias and station history. (The change is explained here.) As you can see in the graph I linked above, the new adjustments have the interesting effect of substantially reducing the rate of temperature increase, primarily over the second half of the twentieth century. It’s more noticeable in the data set based solely on meteorological stations, less so in the land-ocean temperature index.
update: Looks like the graph I linked to and the page explaining the change in the bias adjustment has been taken down.
Nice try 🙂
Check the March temperature difference for the continental United States at http://www.cpc.ncep.noaa.gov/products/tanal/thirtydayf.html. Although we are just coming off an El Nino, it appears that we might be heading into anothe La Nina, which will mean a hot, dry summer for the Southeast. If this keeps on, Georgia might start looking more like New Mexico.
Generally the new monthly data doesn’t get posted on the GISS site until about a week into the following month, so this is a bit mysterious on more than one level.