According to GISS NASA, the average global surface temperature anomaly for September was 0.91 °C, which is just 0.01 °C higher than the previous hottest September in 2014.
The average for the eight months to the end of September is 1.03 °C, which is 0.23 °C higher than the previous hottest January to September period in 2015, which with the latest data had an anomaly of 0.80 °C.
There are now twelve in a row of "hottest months" from October 2015 to September 2016 (that is, hottest October, hottest November etc). If we could look back over the entire Holocene, it's probably more than 7,000 years since there was a similar run of hottest months on record, that is, not since the Holocene climatic optimum (it's probably hotter now than it was back then).
Update: It's just been pointed out to me that the latest revisions put June 16 temperature (0.75 C) below that of June 98 and June 15 (equal 0.78 C). That means that there were now eight months in a row of "hottest" - from October to May inclusive. Then another three hottest months from July to September.
Here is a chart of the average of 12 months to September each year. The 12 months to September 2016 averaged 1.03 °C above the 1951-1980 mean and was 0.23 °C hotter than the 12 months to September 2015:
Now no La Niña?
You can see the global mean temperature trend by month in the chart below, for the strongest El Niño years since 1950, which were followed by a La Nina. I've included the 2015/16 period for comparison. NOAA has put back the La Nina watch. The BoM ENSO update is still on watch status (it never came off).
Not counting 2015/16, of the seven very strong, strong and strong to moderate El Ninos since 1950, there were only three that were followed by a La Nina. The chart spans a three year period. That is, for the 2015-16 El Niño and subsequent, it goes from January 2015 to December 2017, or would if the data allowed. (For a more detailed explanation see the HW articles: El Niño to La Niña years with more detail here.)
|Figure 3 | Global mean surface temperature for strong or moderate/strong El Nino years that were followed by a La Nina. Data source: GISS NASA|
Where was it hot?
Last month it was again hot almost everywhere. Much of the northern hemisphere was very hot. Part of Antarctica is extremely hot and part is rather cool. There was also a cool patch over south-west Western Australia, which IIRC had the coldest September ever. The cooler patch south of Greenland is still there, too.
|Figure 4 | Map showing mean surface temperature, anomalies for September, from the 1951-1980 mean. Source: GISS NASA|
Below is August for comparison:
|Figure 5 | Map showing mean surface temperature, anomalies for August, from the 1951-1980 mean. Source: GISS NASA|
Year to date average surface temperature
The chart below tracks the year to date. Each point on the plot is the average of the year to that month. For 2016, the last point is the average of all months to date including September. This year is tracking well above 2015, partly because of the El Niño. To drop below the average for 2015, the average anomaly for the next three months would need to be less than 0.39 °C:
|Figure 6 | Global mean surface temperature, progressive year to date to September 2016. Data source. GISS NASA|
The next three months would have to be the temperatures of 16 years ago...
Given the expectation that this will be another "hottest year", below is a chart showing the average temperature for the three months from October to December from 2000 onwards. Only one year had the October to December average below 0.39 C and that was 16 years ago in 2000. (The red line is the average year to date for 2016.)
Related HotWhopper articles
- Crikey! Hottest August on record - vies with July for hottest month ever - September 2016
- Hottest July on record - global surface temperature with year to date - August 2016
- Hottest June on record - global surface temperature with year to date - July 2016
- El Niño to La Niña years - May 2016 with more detail here
- Hottest May on record with year to date temperature - June 2016
- Seven in a row: April is the hottest April on record, a 7000 year record? - May 2016
- Hottest March on record, tracking El Niño, and a year to date comparison - April 2016
- Hottest February by far at a whopping 1.35 C above the 1951-1980 mean - March 2016
- Hottest January on record, with El Niño years comparison - February 2016