Update on August Global Average Surface Temperature Anomaly, with information about sources.

This replaces a post of three days ago, which had some errors in numbering. In a few cases data was filled with the wrong JMA stations, which created a few large errors. I now use a more conservative correspondence rule.

Last week I posted provisional results for August, noting that the number of stations reported by NOAA's GHCN was unusually low, and didn't seem to be improving. In particular, no results for China, Iran or Kazakhstan.

NASA GISS had a similar difficulty, reported here. They mention mainly problems in Africa, so maybe they have alternative China data. It is available; China has sent in their Climat forms. NOAA has posted an August average with, as far as I can see, no caveats. So I looked for other accessible data.

The best I found was JMA, which does have that Climat data. So I combined that with the GHCN data (details below)(. This gave me about 300 more stations outside US (ROW), and 100 within. The number of US stations is still a lot less than usual, but more than we need. I now have 2515 stations in ROW, which is less than the 3200 I would normally use as publishable, but does now at least have reasonable coverage of China and Kazakhstan. I'll show the map below.

The change amplified the rise since July, from 0.881°C to 0.981°C (last post was 0.968°C). That is now a substantial rise of 0.1°C, but still with some missing data. GISS got a provisional rise of 0.13°C; NOAA of 0.07°C.

Here is the map of stations now included, with the map for September 2024 for comparison:


Here is the temperature map, using the FEM-based map of anomalies. Use the arrows to see different 2D projections.

Combination rule

The JMA gives the name of station and country, but these don't reliably match GHCN letter by letter. They give the WMO number. GHCN gives a code of 11 chars, often ending in the WMO number. My earlier problem was that sometimes it doesn't, and in fact there can be very different stations with the last 5 chars. But if it is a WMO number, usually it will be preceded with 3 zeroes, so I made that a requirement. I use JMA only where GHCN is missing.



As always, the 3D globe map gives better detail. There are more graphs and a station map in the ongoing report which is updated daily.

This post is part of a series that has now run since 2011. The TempLS mesh data is reported here, and the recent history of monthly readings is here. Unadjusted GHCN is normally used, but if you click the TempLS button there, it will show data with adjusted, and also with different integration methods. There is an interactive graph using 1981-2010 base period here which you can use to show different periods, or compare with other indices. There is a general guide to TempLS here.


The reporting cycle starts with the TempLS report, usually about the 8th of the month. Then when the GISS result comes out, usually about the 15th, I discuss it and compare with TempLS. The TempLS graph uses the FEM solution on a regular near equal area grid on the sphere ; the residuals are displayed more directly using a triangular grid in a WebGL plot here.

A list of earlier monthly reports of each series in date order is here:

1. NCEP/NCAR Reanalysis report
2. TempLS report
3. GISS report and comparison with TempLS