According to the Met Office and Hadley Centre data set, HadCRUT4, the temperature for July 2018 was 0.591°C above the 1961-1990 average. This is slightly higher than the anomaly in June of 0.576°C, but still down on the warmest anomaly months of March and April. Overall the year remains pretty flat with only a tenth of a degree separating all months.
This places July 2018 as the 6th warmest July in the HadCRUT data set.
According to the NASA GISTEMP data set, July 2018 was 0.78°C above the 1951-1980 base period. This is almost identical to the anomaly for last month and continues something of a downturn compared with earlier in the year when the anomaly was over a tenth of a degree warmer. In a way this seems surprising when you consider how hot it has been over much of globe, and is a good illustration of why it's important to look at the whole picture and not just the part of the world you are living in.
It also demonstrates a curious discrepancy between the satellite and surface data sets. All surface data sets have shown, at least using 12 month smoothing, a fairly consistent cooling since the height of the 2016 El Niño, whereas satellite data shows most of the cooling stopping in 2017, with temperature hardly changing since then.
All this is relative though. GISTEMP might be a lot cooler than it was in 2016, but 2018 was still the 3rd warmest July on record, with the last 3 July's being the three warmest on record, with 2015 being the equal 4th warmest July.
As the graph shows the last three years have all had relatively warm Julies. Yet despite this, July 2018 was slightly below the trend counting all months and starting in 1970. This trend is 1.80°C / century.
The average anomaly for 2018 so far is 0.817°C, continuing to decline from a peak of 0.840°C in April. Despite this my prediction for 2018 rose ever so slightly. It now stands at 0.823 ± 0.079°C, compared with the prediction based on data up to June of 0.820 ± 0.087°C.
NB, I don't always spell this out but when I quote the previous months prediction I'm recalculating it with current data. This is not necessarily going to be the same as the actual prediction I made the previous month. Differences can arise because the earliest figure published around two weeks after the end of the month will be modified over the coming weeks. I prefer to use the most recent data, and it's easier to just read the corrected values from my R script than go back over previous postings. For what it's worth my initial prediction made from June 2018 was 0.825°C, so the prediction from July is slightly down not up, but it really makes almost no difference.
That disclaimer over, the prediction is now increasingly that 2018 will be the 4th warmest year on record, placing it between 2010 and 2014. There's around an 85% chance of it finishing exactly in 4th place, but only just over 1% that it will finish below 2010. There's around 14% chance that it will finish above 2014 for 3rd or higher, including a small but non-negligible chance of finishing in 2nd place.
| Rank | Year | Anomaly | Probability | Cumulative |
|---|---|---|---|---|
| 1 | 2016 | 0.99 | 0.01% | 0.01% |
| 2 | 2017 | 0.9 | 3.55% | 3.56% |
| 3 | 2015 | 0.86 | 10.67% | 14.23% |
| 4 | 2014 | 0.73 | 84.52% | 98.74% |
| 5 | 2010 | 0.7 | 1.13% | 99.87% |
| 6 | 2005 | 0.67 | 0.11% | 99.98% |
| 7 | 2013 | 0.64 | 0.02% | 100.00% |
According to Remote Sensing Systems (RSS) satellite data, the global anomaly for July 2018 was 0.631°C above the 1979-1998 average. This makes 2018 the third warmest July in the RSS record. The only years warmer were 2010 and 2016, both strong El Niño years.
The trend for all months since 1979 is 1.96°C / century. This July was slightly above the trend. The average over the last 12 months remains above the trend line as.
My simple statistical prediction for the year, is that 2018 will be 0.535±0.081°C. This is slightly up on last month's prediction of 0.527±0.095°C. For comparison the actual average for the first 7 months is 0.514°C, so this will require the following months to warm up slightly compared with the start of the year.
On this basis there is now around a 75% chance that RSS will finish in 6th place, between 2014 and 2015. This is virtually unchanged from last months prediction, but the probability of finishing below 6th place has diminished, from around 1 in 30, to 1 in 100. This means there is now slightly more chance (~25%) of beating 2015, in which case 5th, 4th or 3rd are still possible.
| Rank | Year | Anomaly | Probability | Cumulative |
|---|---|---|---|---|
| 1 | 2016 | 0.76 | 0.00% | 0.00% |
| 2 | 2017 | 0.65 | 0.40% | 0.40% |
| 3 | 2010 | 0.6 | 6.79% | 7.19% |
| 4 | 1998 | 0.58 | 6.32% | 13.51% |
| 5 | 2015 | 0.56 | 9.92% | 23.43% |
| 6 | 2014 | 0.44 | 75.47% | 98.90% |
| 7 | 2005 | 0.44 | 0.15% | 99.05% |
| 8 | 2003 | 0.4 | 0.89% | 99.94% |
| 9 | 2013 | 0.39 | 0.02% | 99.96% |
| 10 | 2007 | 0.39 | 0.00% | 99.97% |
| 11 | 2002 | 0.38 | 0.01% | 99.97% |
| 12 | 2006 | 0.35 | 0.03% | 100.00% |
Dr Roy Spencer has announced the latest monthly global temperature anomaly according to the UAH satellite data set. The anomaly for July was 0.32°C warmer than the 1981 - 2010 average. This is an increase of around 0.1°C over the June anomaly, and makes July the warmest anomaly of the year so far. This is the 4th warmest July on record, only beaten by the El Niño years of 1998, 2010 and 2016.
July was very slightly above the trend line, which shows overall temperature rise at 1.28°C / century. It also means the twelfth month moving average stopped falling for this month.
With half the year already set and temperatures remaining very close to expected values, there was little change in the central prediction for 2018. This is now predicted to be 0.255 ± 0.074°C, compared with the prediction from June of 0.244 ± 0.091°C. This can be compared with the current average anomaly for the year of 0.233°C.
The most likely result is still for 2018 to be slightly cooler than 2015, making it the 6th warmest year in the UAH record. There is now around a 1 in 3 chance of 2018 finishing above 2015 for 5th place, a 1 in 2 chance of finishing in 6th place, and a 1 in 6 chance of finishing below 2002 for 7th or lower.
| 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 | 0.11% | 0.11% |
| 4 | 2010 | 0.34 | 1.38% | 1.49% |
| 5 | 2015 | 0.27 | 33.94% | 35.43% |
| 6 | 2002 | 0.22 | 49.64% | 85.07% |
| 7 | 2005 | 0.2 | 8.21% | 93.29% |
| 8 | 2003 | 0.19 | 3.25% | 96.54% |
| 9 | 2014 | 0.18 | 0.98% | 97.52% |
| 10 | 2007 | 0.16 | 1.84% | 99.36% |
| 11 | 2013 | 0.14 | 0.49% | 99.85% |
| 12 | 2001 | 0.12 | 0.12% | 99.97% |
| 13 | 2006 | 0.11 | 0.00% | 99.98% |
| 14 | 2009 | 0.1 | 0.02% | 99.99% |
Despite hot weather in many parts of the world the pattern from UAH at least continues to be pretty stable. So far my mid-range forecast has barely moved, with July being almost identical to the forecast from January.
