Global Temperature Just Short of Record in September, Says NOAA

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.


Figure 1. Departure of temperature from average by region for September 2016, which fell just short of September 2015 in NOAA’s database as the warmest September for the globe since record keeping began in 1880. Large swaths of much-warmer-than-average conditions could be found across the Americas, Africa, Eurasia, and adjacent oceans, with pockets of record warmth scattered across the globe. Image credit: NOAA National Centers for Environmental Information (NCEI).

A year-plus streak of global records draws to an end
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. Ocean-only temperatures this September were 0.04°C (0.07°F) cooler than the record warmth of September 2015, while land-only temperatures were 0.11°C (0.20°F) above the previous land-only record from September 2015. (Since most of Earth’s surface is covered by ocean, the land-plus-ocean reading is dominated by the ocean-only temperatures, thus keeping September 2016 just short of the land-plus-ocean record) For the lowest 8 km of the atmosphere, global satellite-measured temperatures in September 2016 were tied for warmest with 1998 for any September in the 38-year record, according to the University of Alabama in Huntsville (UAH).

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. NOAA’s global surface temperature for the year so far (January-September 2016) is an eye-opening 0.78°C (1.40°F) above the 20th-century average and 0.08°C (0.14°F) warmer than the previous January-to-September record, set in 2015 (see Figure 2 below).

Temperatures would have to plummet at an almost unthinkable pace between now and December in order to keep 2016 from becoming the warmest year in global record-keeping. Gavin Schmidt, director of NASA’s Goddard Institute of Space Studies, has maintained for months that there is a better-than-99 percent chance of 2016 ending up as Earth’s third consecutive hottest year on record. On October 17, Schmidt concluded that a new annual record for 2016 now “seems locked in.”

As the end of the year approaches, it will be difficult for temperatures to top the monthly records set in late 2015 and early 2016. At the same time, even a modest dip in global temperatures would still keep readings close to the record pace of 2015-16, and above all or nearly all other years in the 136-year database.


Figure 2. Departure from the 20th-century average for the global January-through-September temperature for the years 1880 - 2016. This year has seen by far the warmest temperatures on record for the year-to-date period. Image credit: NOAA/National Centers for Environmental Information (NCEI).

NOAA expects a La Niña event this fall, but probably a weak one
Sea surface temperatures (SSTs) in the Niño3.4 monitoring region of the eastern Pacific have been near or beyond the threshold for a weak La Niña since mid-July, but the atmospheric conditions that normally accompany La Niña have been slower to evolve. In September, NOAA dropped the La Niña Watch that was in place for several months, but reinstated it on October 13, thanks to a pronounced cooling of SSTs in late September and early October that caused the atmosphere to begin responding in a La Niña-like fashion. According to the October ENSO forecast from NOAA’s Climate Prediction Center, weak La Niña conditions are now favored to exist during the remainder of the Northern Hemisphere fall (70% chance), and persist through the winter (55% chance.)

Australia’s Bureau of Meteorology retained its La Niña watch in its biweekly update on October 11, saying “the majority of international climate models indicate the tropical Pacific is likely to remain at ENSO neutral levels through to the end of the 2016–17 summer. Two of the eight models suggest brief, weak La Niña levels are possible towards the end of 2016.” (Australia’s oceanic threshold for La Niña and El Niño is higher than NOAA’s: the Niño3.4 region must be at least 0.8°C warmer or cooler than average, rather than 0.5°C, though Australia doesn’t require those temperatures to persist for months as NOAA does.) The Japan Meteorological Agency has gone further; for the second straight month, their monthly update has concluded that “it is considered that La Niña conditions are present in the equatorial Pacific.” The JMA uses the Niño3 region, which overlaps with the Niño3.4 region but extends further east.

Arctic sea ice hits its fifth lowest September extent on record
The rate of September sea ice gain in the Arctic was above average last month, after sea ice extent bottomed out at the second lowest yearly extent ever observed early in the month (see our post here on that event). As a result, September 2016 Arctic sea ice extent came in at the fifth lowest in the 38-year satellite record, according to the National Snow and Ice Data Center (NSIDC). The minimum extent for the year, set on September 10, tied with the minimum set in 2007 for the second-lowest on record. The Arctic’s sea ice has grown so slowly in recent days that the extent on October 18 was in a virtual tie with 2007 and 2012.

One billion-dollar weather disaster in September 2016: Typhoon Meranti
According to the September 2016 Catastrophe Report from insurance broker Aon Benfield, one billion-dollar weather-related disaster hit the planet in September: Typhoon Meranti, which killed 44 people in China, Taiwan and the Philippines on September 13 - 16 and did $2.4 billion in damage. Two other tropical cyclones in September fell just short of being billion-dollar disasters: Hurricane Hermine in the U.S. ($800 million in damage) and Typhoon Megi, which hit Taiwan at Category 3 strength and China at Category 1 strength, doing $940 million in damage.

Additionally, a severe weather outbreak in the U.S. Plains, Midwest and Mississippi Valley on May 7 - 10 and a flood disaster April 15 - 19 in the U.S. Plains/Rockies accumulated enough damage claims to be rated billion-dollar disasters by the end of September. Between January - September 2016, there were 27 billion-dollar weather disasters globally. This is the fifth greatest number of such disasters since 1990, with only 2013 (41), 2010 (40), 2011 (35) and 2014 (29) with more.

For the U.S., Aon Benfield and NOAA counted twelve billion-dollar weather disasters during January - September 2016, which is the second highest number of such disasters on record since 1980 (the record: sixteen in 2011.) Most interesting is that NOAA classifies four of these as inland flood events, which doubles the previous record of two inland flood events in a year. NOAA emphasizes ”This is a notable record, further highlighted by the numerous other record flooding events that have impacted the U.S. in 2016.”


Figure 3. U.S. billion-dollar weather disasters (adjusted for inflation using the Consumer Price Index, or CPI) since 1980 (colored bars, scale on the left axis) and damage done by these disasters (grey line with a shaded 95% confidence interval, scale on the right axis.) The 1980–2015 annual average is 5.2 events (CPI-adjusted); the annual average for the most recent 5 years (2011–2015) is 10.8 events (CPI-adjusted). Image credit: NOAA.

Here is Aon Benfield’s tally of billion-dollar weather disasters globally for January - September 2016:

1) Flooding, Yangtze Basin, China, 5/1 - 8/1, $28.0 billion, 475 killed
2) Flooding, Louisiana U.S., 8/9 - 8/16, $10 - $15 Billion, 13 killed
3) Flooding, Germany, France, Austria, Poland, 5/26 - 6/6, $5.5 billion, 17 killed
4) Drought, India, 1/1 - 6/30, $5.0 billion, 0 killed
5) Flooding, Northeast China 7/16 - 7/24, $5.0 billion, 289 killed
6) Wildfire, Fort McMurray, Canada, 5/2- 6/1, $5.0 billion, 0 killed
7) Severe Weather, Plains-Southeast U.S., 4/10 - 4/13, $3.75 billion, 1 killed
8) Severe Weather, Rockies-Plains-Southeast-Midwest U.S., 3/22 - 3/25, $2.5 billion, 0 killed
9) Super Typhoon Meranti, China, Taiwan, Philippines, 9/13 - 9/16, $2.4 billion, 44 killed
10) Flooding, China, 6/18 - 6/23, $2.3 billion, 68 killed
11) Winter Weather, East Asia, 1/20 - 1/26, $2.0 billion, 116 killed
12) Severe Weather, Plains-Midwest U.S., 4/29 - 5/3, $1.75 billion, 6 killed
13) Tropical Cyclone Roanu, Sri Lanka, India, Bangladesh, Myanmar, China, 5/14 - 5/21, $1.7 billion, 135 killed
14) Drought, China, 1/1 - 3/1, $1.6 billion, 0 killed
15) Drought, Zimbabwe, 6/1 - 8/10, $1.6 billion, 0 killed
16) Flooding and Severe Weather, Plains-Midwest-Southeast-Northeast U.S., 3/4 - 3/12, $1.5 billion, 6 killed
17) Typhoon Nepartak, Philippines, Taiwan, China, 7/8 - 7/9, $1.5 billion, 111 killed
18) Severe Weather, Plains-Southeast U.S., 3/17 - 3/18, $1.4 billion, 0 killed
19) Tropical Cyclone Winston, Fiji, 2/16 - 2/22, $1.4 billion, 44 killed
20) Flooding, Argentina and Uruguay, 4/4 - 4/10, $1.3 billion, 0 killed
21) Severe Weather, Plains-Midwest U.S., 5/21 - 5/28, $1.3 billion, 1 killed
22) Severe Weather, Plains-Midwest-Southeast-Northeast U.S., 2/22 - 2/25, $1.2 billion, 10 killed
23) Severe Weather, Netherlands, 6/23 - 6/24, $1.1 billion, 0 killed
24) Severe Weather, Plains-Rockies U.S., 7/28 - 7/29, $1.0 billion, 0 killed
25) Flooding, Texas U.S., 4/15 - 4/19, $1.0 billion, 9 killed
26) Severe Weather, Plains-Midwest-Mississippi Valley U.S., 5/7 - 5/10, $1.0 billion, 2 killed
27) Winter Weather, Eastern U.S., 1/21 - 1/24, $1.0 billion, 58 killed

And here are the three disasters from September 2016 in more detail:


Disaster 1. After topping out as one of Earth’s top-ten strongest tropical cyclones on record, with a central pressure of 890 mb and sustained winds of 190 mph, Super Typhoon Meranti weakened to Category 2 strength before making landfall in China’s Fujian Province on September 15. Meranti killed 42 people and did $2.3 billion in damage to China. In Tawian, two people were killed, and damage was over $70 million. Above, we see the eye of Meranti directly over the Philippines’ Itbayat Island in a moonlight image from Japan’s Himiwari-8 satellite taken at 17:32 UTC September 13, 2016. Itbayat recorded sustained winds of 112 mph (10-minute average) and a pressure of 934 mb at 1 am local time, 32 minutes prior to this image. At the time, Meranti was a Category 5 storm with 185-mph winds and a central pressure of 890 mb. No deaths or injuries were reported on the island, but there was heavy damage.


Disaster 2. Extreme rainfall of up to 17 inches created widespread urban flooding in Houston and surrounding suburbs April 15 - 19. Over 1,000 homes and businesses were damaged, and there were more than 1,800 high water rescues. It was the most widespread flood event to affect Houston since Tropical Storm Allison in 2001. Above, we see a drone image of flooding in north Houston on April 20, 2016. Image credit: wunderphotographer Moussifer.


Disaster 3. Tornadoes and severe storms caused widespread damage across the Plains and Central states (NE, MO, TX, OK, KS, CO, IL, KY, TN) May 7 - 10. The damage was greatest in Nebraska and Missouri. In this image, we see a rotating supercell thunderstorm with a wall cloud over Stillwater, OK, on May 9, 2016. Image credit: wunderphotographer gunhilda.

India’s monsoon season ends with slightly below-average rains
India, whose $5 billion drought was Earth's fourth most expensive weather-related natural disaster through September of 2016, received decent monsoon rains in 2016 after two straight years of poor rains. According to the India Meteorological Department, monsoon rains during the period June 1 - September 30, 2016 were about 3% below average. This year’s monsoon rains wreaked considerable death and damage, though. Through the end of August, monsoon floods had killed at least 510 people in India and caused at least $150 million in damage, with the Ganges River reaching the highest levels ever recorded at four locations in northern India. Additional heavy monsoon rains in India’s Telangana and Andhra Pradesh states led to catastrophic flooding during the second half of September, killing at least 28 people and causing $479 million in damage. The monsoon is now in steady retreat across India, but at a slower pace than usual.

Notable global heat and cold marks set in September 2016
Hottest temperature in the Northern Hemisphere: 51.2°C (124.2°F) at Mitribah, Kuwait, 4 September
Coldest temperature in the Northern Hemisphere: -38.6°C (-39.6°F) at Geo Summit, Greenland, 20 September
Hottest temperature in the Southern Hemisphere: 44.0°C (111.2°F) at Villamontes, Bolivia, 12 September
Coldest temperature in the Southern Hemisphere: -82.2°C (-116.0°F) at Dome Fuji, Antarctica, 9 September
(Courtesy of Maximiliano Herrera.)

Major weather stations that set (not tied) new all-time heat or cold records in September 2016 (Courtesy of Maximiliano Herrera)
Fez Airport (Morocco) max. 45.1°C,  5 September
Ibiza Airport (Spain) max. 38.4°C,  5 September
Lugo (Spain) max. 41.6°C, 6 September
Col Major-Mt. Blanc (Italy) max. 6.3°C, 7 September; increased to  7.2°C on 29 September
Saint Laurent do Moroni (French Guiana, France) max. 38.0°C, 27 September:  New territorial record high for French Guiana
Caravelle (Martinique) max 36.1°C, 15 September

One all-time national heat record set or tied in September 2016
One nation or territory—French Guiana--set an all-time heat record in September 2016. From January through September 30, 2016, a total of 21 nations or territories tied or set all-time records for their hottest temperature in recorded history. This breaks the record of eighteen all-time heat records in 2010 for the greatest number of such records set in one year. Also, one all-time cold temperature record has been set so far in 2016 (in Hong Kong.) "All-time" record here refers to the warmest or coldest temperature ever reliably reported in a nation or territory. The period of record varies from country to country and station to station, but it is typically a few decades to a century or more. Most nations do not maintain official databases of extreme temperature records, so the national temperature records reported here are in many cases not official. Our data source is international weather records researcher Maximiliano Herrera, one of the world's top climatologists, who maintains a comprehensive list of extreme temperature records for every nation in the world on his website. If you reproduce this list of extremes, please cite Maximiliano Herrera as the primary source of the weather records. Here are 2016's all-time heat and cold records as of October 1:

French Guiana broke its all-time hottest record on September 27, 2016, when the mercury hit 38.0°C (100.3°F) at Saint Laurent du Moroni.

The Marshall Islands set its all-time hottest record on August 24, 2016, when the mercury hit 35.6°C (96.1°F) at Utirik Atoll.

The Cayman Islands (United Kingdom territory) tied its all-time hottest record on August 21, 2016, when the mercury hit 34.9°C (94.8°F) at Owen International Airport.

The British Virgin Islands [United Kingdom territory] set its all-time hottest record on July 22, 2016, when the mercury hit 35.0°C (95.0°F] at Terrance B. Lettsome International Airport.

Iraq set its all-time hottest record on July 22, 2016, when the mercury hit 53.9°C (129.0°F) at Basrah.

Iran tied its all-time hottest record on July 22, 2016, when the mercury hit 53.0°C (127.4°F) at Delhoran.

Kuwait set its all-time hottest record on July 21, 2016, when the mercury hit 54.0°C (129.2°F) at Mitribah.

Guernsey (United Kingdom territory) tied its all-time hottest record on July 19, 2016, when the mercury hit 35.0°C (95°F) at the small island of Alderney.

Hong Kong Territory (China) tied its all-time hottest record on July 9, 2016, when the mercury hit 37.9°C (100.2°F) at Happy Valley.

Niger set its all-time hottest record on June 8, 2016, when the mercury hit 49.0°C (120.2°F) at Bilma.

Palau tied its all-time hottest record on June 8, 2016, when the mercury hit 34.4°C (93.9°F) at Koror AWS.

India set its all-time hottest record on May 19, 2016, when the mercury hit 51.0°C (123.8°F) at Phalodi.

Maldives set its all-time hottest record on April 30, 2016, when the mercury hit 35.0°C (95.0°F) at Hanimaadhoo.

Thailand set its all-time hottest record on April 28, 2016, when the mercury hit 44.6°C (112.3°F) at Mae Hong Son.

Cambodia set its all-time hottest record on April 15, 2016, when the mercury hit 42.6°C (108.7°F) at Preah Vihea.

Burkina Faso set its all-time hottest record on April 13, 2016, when the mercury hit 47.5°C (117.5°F) at Dori.

Laos set its all-time hottest record on April 12, 2016, when the mercury hit 42.3°C (108.1°F) at Seno.

Vanuatu in the South Pacific set its all-time hottest record on February 8, 2016, when the mercury hit 36.2°C (97.2°F) at Lamap Malekula.

Tonga set its all-time hottest record on February 1, 2016, when the mercury hit 35.5°C (95.9°F) at Niuafoou.

Wallis and Futuna Territory (France) set a new territorial heat record with 35.8°C (96.4°F) on January 10, 2016 at Futuna Airport. This is the second year in a row that Wallis and Futuna has beaten its all-time heat mark; the previous record was a 35.5°C (95.9°F) reading on January 19, 2015 at the Futuna Airport.

Botswana set its all-time hottest record on January 7, 2016, when the mercury hit 43.8°C (110.8°F) at Maun.

Hong Kong Territory (China) set its all-time coldest mark on January 24, 2016, when the mercury dipped to -6.0°C (21.2°F) at Tai Mo Shan (elevation 950 meters.) Tai Mo Shan has a period of record going back to 1996; the coldest temperature near sea level since record keeping began at the Hong Kong Observatory in 1884 was 0°C (32°F) on January 18, 1893.

Jeff Masters and Bob Henson