New reports out from NOAA and NASA show that we’ve yet again lived through a record-breaking month of warmth—global temperature readings revealed that July 2016 was “absolutely the hottest month” ever recorded, according to NASA climatologist Gavin Schmidt. This past July was 0.87°C (1.57°F) hotter than the 20th century average in NOAA’s monthly climate report, and the month finished up 0.84°C (1.55°F) above average in NASA’s findings.
Global temperature anomalies in July 2016. Image credit: NOAA
Data collected by thousands of observation stations on land and at sea discovered that temperatures were either the warmest ever recorded or much warmer than average across wide swaths of the planet. Areas that saw all-time record heat included a small part of the southeastern United States, as well as portions of southern Asia and the Pacific Ocean.
Not only was last month the warmest July on record, but this record temperature anomaly made it the warmest month ever recorded. July typically sees the year’s highest average global temperature because it’s the peak of summer heating in the Northern Hemisphere, which has 68 percent of the world's land, making it more prone to extreme heat than the Southern Hemisphere as a whole. This year’s warming trend was likely given a measurable assist by El Niño, the abnormal warming of the equatorial waters of the eastern Pacific Ocean. The warm water of an El Niño can raise air temperatures and alter weather patterns in a way that creates abnormally warm weather elsewhere in the world.
If it seems like you’ve seen this news before, there’s good reason for it—NOAA found that this July was the 15th month in a row with record-breaking global temperature anomalies. Every month since May 2015 has broken its respective all-time warmest record. The unbroken streak of anomalies made 2015 the world’s warmest year since instrumental records began in 1880. Unfortunately, 2014 broke the record for the hottest year too, and it looks like 2016 is on pace to break 2015's record.
Yearly global temperature anomalies between 1880 and 2015. Image credit: NOAA
So far, the global temperature anomaly in 2016 through July is +1.03°C (1.8°F), which is the first time we’ve ever recorded temperature a full one degree above normal. NOAA’s records show that the average global temperature has been at least a little above normal every month except one for the past 455 months, or since September 1978. The lone below-average month during that 38-year period was December 1984, when the global average temperature was 0.09°C (0.16°F) below normal.
A few tenths of a degree Celsius above normal doesn’t seem like a very big deal, but just like the small temperature fluctuations brought about by an El Niño or La Niña, these seemingly tiny temperature anomalies can have a significant impact on both short-term weather and long-term climate trends. If the long-term trend of rising temperatures continues, some of the likely effects will include more frequent droughts, more intense heat waves, more intense bouts of heavy rain, and rising sea levels.