Last month I posted a chart of the progressive year-to-date global average surface temperature, from GISS. This is the update with April included. I'll repeat the explanation with each update and add what seem to be things to watch.
- April was an average of 0.75°C above the 1951-1980 mean.
- From and including December 2014, every month has been the second hottest in the record for that month, except for March 2015, which was the 3rd hottest March on record.
- Every month this year has been at least 0.75°C above the 1951-1980 mean.
- The progressive year to date average up to and including April is 0.79°C above the 1951-1980 mean.
Explaining the chart
The chart is a progressive year to date average for all years from 1995 to the present. What that means is for January each year, it just shows the anomaly for January. For February it shows the average of January and February for each year. For March, its the average of the monthly anomaly from January to March.
If you look at December, each year shows the annual average temperature for the full year. For November, each year has the average for the year up to November, not including December. (As before, I've made it extra large because of all the fine detail.)
|Data Source: NASA GISS|
2015 is still ahead of the pack so far. The years to watch are 2014, 2010 and 2005. I've plotted them with slightly thicker lines so they stand out more easily.
The coldest year of the lot was 1996, which still ended up more than 0.3°C above the 1950 to 1981 average. The next time someone tries to tell you that "it hasn't warmed since 1996" then show them this chart :)
Related updatesYTD including March
YTD including May