Sunday, May 15, 2016

April GISS down 0.18°C - hottest April in record.

In fact, GISS first exceeded 1°C in October 2015, so until then everything over 1°C is a monthly record. October was 1.07, so April is getting back to that. GISS 2016 went from 1.29°C in March to 1.11°C in April. The drop in GISS was higher than other indicators; TempLS mesh was down 0.075°C (China increased it); NCEP/NCAR down 0.15°C. For the lower troposphere, RSS was down about 0.09°C, UAH down 0.02°C.

The Arctic was cooler, and GISS is sensitive to that. Other regional changes were much as discussed in the TempLS post. As usual, I'll show the GISS map and the corresponding TempLS below the fold.

In other news, Arctic Sea Ice is still melting fast..

Here is the GISS map for April:

And here is the TempLS mesh spherical harmonics map for April:


  1. Slightly colder than expected (by me), but at least a tie with January for third warmest monthly anomaly ever.
    The GHCNv3 Arctic cooling sickness has unfortunately spread, and includes now also Svalbard. The algorithm finds the persistent hotspot spurious (6 months with about +10 C anomaly since Nov 2015 over Svalbard, Franz Josef and Ostrov Vize Islands), and has simply removed the data.
    However, I don't think the global effect of this Arctic adjustment is very large, maybe -0.02 C, which can be seen in record high February which has slipped down from 1.35 to 1.33 C.
    The effect of station adjustment kan be studied here
    Typically GHCNv3 removes about 600 stations worlwide each month, or about 25% of the total. In areas with redundancy this doesn't matter, but areas where stations are more sparse (e g Brazil and parts of Africa) are affected as well

  2. Nick,

    Your amazingly useful tool for looking at Arctic temperatures... broken. It seems to be displaying last year's temps.


    1. William,
      Thanks. I'll look into it later today.

    2. Thanks again, William.
      I think it is fixed now.

    3. Sorry to report it is not fixed when I look at it. It displays "2015" at the top of the graph, data through day 200, obviously last year's data (I had been checking the graph daily to look for signs of early melt this year, so I recognized the pattern had changed).

    4. Confirming it is fixed now. thanks.