Temperature Update - September 2018, HadCRUT

According to the Met Office Hadley Centre data set (HadCRUT, September 2018 was 0.596°C above the 1961-1990 average. This is virtually the same as the anomaly for the last two months. In fact the last three months have been within 0.005°C of each other.

This makes 2018 the 4th warmest September in the HadCRUT record. (To two decimal places it would be equal third with 204 at 0.601°C.)

In general temperatures continue to be a bit below the trend since 1970 of 1.73°C / century.

The average anomaly for 2018 so far is 0.585°C, and my prediction is 0.590±0.056°C, compared with 0.593±0.070°C from last month.

The predicted value remains very close to 2014, the current 4th warmest year, at 0.580°C, so it's still on a knife edge where 2018 will finish in the HadCRUT records. Currently I give it around 64% of beating 2014 for 4th place, but if it does finish below this it could plausibly be as low as 8th place, owing to a number of calendar years being very close together.

HadCRUT4

Rank	Year	Anomaly	Probability	Cumulative
1	2016	0.8	0.00%	0.00%
2	2015	0.76	0.00%	0.00%
3	2017	0.68	0.15%	0.15%
4	2014	0.58	64.21%	64.36%
5	2010	0.56	21.17%	85.52%
6	2005	0.55	8.46%	93.98%
7	1998	0.54	2.12%	96.09%
8	2013	0.51	3.41%	99.51%
9	2003	0.51	0.25%	99.75%
10	2006	0.51	0.04%	99.79%
11	2009	0.51	0.01%	99.80%
12	2002	0.5	0.10%	99.91%
13	2007	0.49	0.04%	99.95%
14	2012	0.47	0.04%	99.99%
15	2004	0.45	0.00%	100.00%

Temperature Update - September 2018 - GISTEMP

According to NASA's GISTEMP the global surface temperature for September was 0.75°C above the 1951-1980 average. In contrast to the satellite data this is only slightly down on the anomaly in August of 0.77°C, and is the equal 6th warmest September on record. It ties with September 2005, and apart from this the last 6 Septembers have been the warmest 6 on record.

Temperature Update - September 2018 - RSS

Data

According to the RSS Satellite data, September was 0.488°C warmer than the 1979 - 1998 average. This is cooler than recent Septembers but a smaller drop than UAH's data for September. It was the 9th coolest September since satellite records began, and the coolest since 2014. It was the 4th coolest monthly anomaly of the year. (Contrast with UAH which has this month as the coldest September in 10 years and the coldest anomaly this year.)

Temperature Update - September 2018 - UAH

Update - 5th October 2018

Added graphs and a correction.

Data

According to the UAH satellite data, global temperatures were 0.14°C above the 1981-2010 average. This makes September the coldest month (by anomaly) of 2018 so far, with the month being the equal 16th warmest September in the 39 year history of satellite data.