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.

GHCN data late this month - interim results August warmer than July.

I have been posting monthly global temperatue anomaly averages for nearly fifteen years, based on land temperaturess from GHCN and ocean temperatures from ERSST. Both come via NOAA. In that time most temperatures are reported during the first few days. This was so last month, but this month there is a definite delay. The counts I use to determine publication were, on August 11:
ROW=3657 US=4705 Sea=3558
US means stations in USA; ROW means land stations elsewhere (both GHCN).

On September 11 we have:
ROW=2016 US=4692 Sea=3557

I normally require ROW>3200 for posting. Not only is the number of ROW stations low, but it has been increasing very slowly.

You might well wonder whether degraded NOAA capability following Trump intervention is responsible. But it is true that the big gaps are in China, Iran and Khazakstan, so current geopolitical tensions may play a role. But they haven't previously.

2000 ROW stations reporting is still respectable; it is far more than used to report in GHCN V3. So I'll post the results, but they may change if a large number of delayed data do turn up. 

The TempLS FEM anomaly (1961-90 base) was 0.968°C in August, up from 0.881°C in July, a rise of 0.081°C. That would make it the third warmest August in the record, just behind 2024 and 2023.

Here is the map of stations reporting:

Here is the corresponding stacked graph:


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

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.

July global surface TempLS down 0.011°C from June.

The TempLS FEM anomaly (1961-90 base) was 0.881°C in July, down from 0.892°C in June. It was the third warmest July in the record, behind 2023 and 2024. Here is the corresponding stacked graph:


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

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.

June global surface TempLS down 0.047°C from May.

The TempLS FEM anomaly (1961-90 base) was 0.883°C in June, down from 0.93°C in May. It was the thirdd warmest June in the record, behind 2023 and 2024. Here is the corresponding stacked graph:


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

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.

May global surface TempLS down 0.188°C from April.

(oops, headline arithmetic corrected - thanks Anon)

The TempLS FEM anomaly (1961-90 base) was 0.915°C in May, down from 1.103°C in April. It was the second warmest May in the record, behind 2024. Here is the corresponding stacked graph:


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

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.

April global surface TempLS down 0.076°C from March.

The TempLS FEM anomaly (1961-90 base) was 1.069°C in April, down from 1.145°C in March. It was the second warmest April in the record, behind 2024. Here is the corresponding stacked graph:


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

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.

March global surface TempLS up 0.04°C from February.

The TempLS FEM anomaly (1961-90 base) was 1.142°C in March, up from 1.093°C in February. It was the second warmest March in the record, a little behind 2024. Here is the corresponding stacked graph:


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

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.