Temperature Update - June 2018, UAH

Halfway through the year and global temperatures continue to be dull, at least according to The University Of Alabama in Huntsville (UAH) satellite data. Dr Roy Spencer announces that the anomaly for June was 0.21°C above the 1981 - 2010 average. This is the same anomaly as for April and 0.03°C above May, and 0.05°C below January, the month with the highest anomaly. So far has only been 0.08°C difference across the range of all months of 2018. This isn't quite the flattest start to a year in UAH history, 1979 and 2002 both had ranges of 0.07°C over the first 6 months, but it is unusual - the average January to June range is 0.25°C.

June 2018 was the 9th warmest June in the UAH data set.

Anomalies for the month of June - UAH6

This graph also gives the impression that Junes as a whole have become more static. Since 2010 there has been relatively little variation in June temperatures compared with the big year to year swings seen previously. I doubt if much can be read into that, it's just a curious observation.

The monthly anomalies continue to be just below the overall trend line.

Monthly UAH6 Anomalies with 12 Month Moving Average and Trend

My prediction for 2018 remains almost unchanged at 0.244 ± 0.091°C, compared with last month's 0.242 ± 0.103°C.

The actual average for the first 6 months of the year is 0.218°C, so this prediction does assume a slight rise in the second half of the year. This in turn is because temperatures are currently just below the trend and the assumption is that it's more likely that temperatures will return to the trend than away from it. It does not take into account any forecasts such as the expected ENSO value.

There has been very little change in the predicted value so far this year, which shouldn't be surprising given the lake of variation in the reported anomalies.

In terms of ranking, UAH continues to show the least certainty, mainly because there is less of a trend in their data. 6th place has the highest probability, but that is still less than 50%. There is around an 80% chance that 2018 will be between 5th and 7th warmest, but with a reasonable possibility it will finish below 7th, possibly as low as 11th. It is unlikely to finish above 5th place.

UAH 6.0

Rank	Year	Anomaly	Probability	Cumulative
1	2016	0.51	0.00%	0.00%
2	1998	0.48	0.00%	0.00%
3	2017	0.38	0.28%	0.28%
4	2010	0.34	2.00%	2.28%
5	2015	0.27	27.08%	29.36%
6	2002	0.22	43.16%	72.52%
7	2005	0.2	11.14%	83.66%
8	2003	0.19	5.78%	89.44%
9	2014	0.18	2.37%	91.81%
10	2007	0.16	4.82%	96.63%
11	2013	0.14	2.20%	98.83%
12	2001	0.12	0.81%	99.64%
13	2006	0.11	0.05%	99.69%
14	2009	0.1	0.21%	99.90%
15	2004	0.08	0.06%	99.95%
16	1995	0.07	0.02%	99.98%
17	2012	0.06	0.01%	99.99%
18	1987	0.05	0.01%	99.99%
19	1988	0.04	0.00%	100.00%