September 2016 was Earth's second warmest September since record keeping began in 1880, said NOAA's National Centers for Environmental Information (NCEI) on Tuesday. In the NOAA database, September 2016 came in 0.89°C (1.66°F) warmer than the 20th-century average for September, and just 0.04°C shy of the record set in September 2015. NASA reported the warmest September in its database, with September 2016 a mere 0.01°C above the previous record, set in September 2014.
September 2016 marked the end of a remarkable streak of 16 consecutive months in which NOAA’s global monthly temperature record was broken, the longest such streak since global temperature records began in 1880.
With the powerful 2015-16 El Niño event having ended early in 2016, the impressive global warmth in recent months can mostly be attributed to the steady build-up of heat-trapping greenhouse gases due to human activities.