Global Temperature: Notable November
At the end of the year global temperatures for 2013 are converging rapidly on a final figure. HadCrut4 has yet to release its Nov data. NASA Giss and NOAA have just done so.
According to the NASA Giss and NOAA global land-ocean temperature databases November 2013 was the warmest since records began in 1880. It has been hailed by some as a significant indication of rising global temperatures. However, a closer look shows some caution is advised.
In the NASA Giss database November is generally the warmest month. It has seven temperature anomalies (hundredths of a degree above 14.00 deg C) above 70. No other year has more than three. December on the other hand is generally the coolest having only one temperature anomaly above 70 and more than its fair share of very cold months (the years 2010, 2011, 2012 were all cold for December.) The warmest December was 75 in 2006 which is statistically identical to November 2013′s 77.
Anomalies above 70 are relatively rare, there are only 27 of them. There are distributed as follows; Jan 3, Feb 3, Mar 3, Apr 2, May 2, June 1, July 1, Aug 0, Sep 1, Oct 3, Nov 7 and Dec 1. The earliest occurs in 1998 – the super El Nino year – and can be found in Feb and June. El Nino years are, as expected, obvious in NASA Giss when observed this way. Jan-Feb-Mar of 2002, Nov-Dec 2006, and Feb-Mar-Apr-May of 2010. This accounts for nine of them. Of those remaining there is no discernable trend. They occur in the early part of the dataset post-1998 as often as in its later part.
NASA Giss also has a Dec-Nov annual temperature which this year is 59, making it the 6th warmest in a tie with 2009 and 2006. Note that 2003 is 58. So the ‘pause’ continues.
NOAA has produced a nice graph that places 2013 in context with previous years in its database. Unusually it shows a steady rise throughout the year and suggests that 2013 may be about the 4th warmest year thanks to a warm November. Click on the image to enlarge.