Global Climate Report - September 2018
2018 year-to-date temperatures versus previous years

« Global Climate Report - September 2018


2018 year-to-date temperatures versus previous years


2018 year-to-date anomalies through September compared to nine warmest years on record
Global Year to Date Temperature Anomalies

This graphic compares the year-to-date temperature anomalies for 2018 (black line) to what were ultimately the nine warmest years on record: 2016, 2015, 2017, 2014, 2010, 2013, 2005, 2009, and 1998. Each month along each trace represents the year-to-date average temperature anomaly. In other words, the January value is the January average temperature anomaly, the February value is the average anomaly of both January and February, and so on.

The average global land and ocean surface temperature for January–September 2018 was 0.77°C (1.39°F) above the 20th century average of 14.1°C (57.5°F)—the fourth highest global land and ocean temperature for January–September in the 1880–2018 record.

The anomalies themselves represent departures from the 20th century average temperature. The graph zooms into the warmest part of the entire history.

2018 is gearing up to end up among the top five warmest years on record. The graph includes several end-of-year results based on the following three scenarios:

  • If each month from October through December had a temperature departure of 0.77°C (1.39°F) (represented by the black squares): 2018 would end up as the fourth warmest year (+0.77°C / +1.39°F) on record, behind 2016 (warmest), 2015 (second warmest), and 2017 (third warmest).
  • If each month from October through December matched the fifth highest temperature departure from average for their respective month (represented by the red circles): 2018 would end up as the fourth warmest year on record at +0.76°C (+1.37°F), behind 2016 (warmest), 2015 (second warmest), and 2017 (third warmest).
    • October value used: 0.73°C / 1.31°F
    • November value used: 0.76°C / 1.33°F
    • December value used: 0.76°C / 1.33°F
  • If each month from October through December matched the 1998 monthly values (represented by the purple triangles): 2018 would tie with 2010 the fifth warmest year on record at +0.70°C (+1.26°F), behind 2016 (warmest), 2015 (second warmest), 2017 (third warmest), and 2014 (fourth warmest).
    • October value used: 0.49°C / 0.88°F
    • November value used: 0.41°C / 0.74°F
    • December value used: 0.58°C / 1.04°F


Citing This Report

NOAA National Centers for Environmental Information, State of the Climate: Global Climate Report for September 2018, published online October 2018, retrieved on December 15, 2018 from https://www.ncdc.noaa.gov/sotc/global/2018/09/supplemental/page-1.

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