Near-Record Global Warmth Continued in October

October 2016 tied with 2003 as Earth's third warmest October since record keeping began in 1880, said NOAA's National Centers for Environmental Information (NCEI) on Thursday. October 2016 was 0.73°C (1.31°F) warmer than the 20th-century October average; the only warmer Octobers were during the two previous years, 2015 and 2014. NASA reported that October 2016 was the second warmest October in its database, behind October 2015. October 2016 was Earth’s coolest month (relative to average) since November 2014, which was 0.69°C (1.24°F) above average. This October was also the first month since April 2015 that failed to set a global heat record in either the NASA or NOAA database.


Figure 1. Departure of temperature from average by region for October 2016, the third warmest October for the globe since record keeping began in 1880. Record warmth was observed across parts of Mexico and the Caribbean, parts of west central Africa, sections of Iraq and southeastern Asia, and western Alaska extending to Far East Russia, where temperatures were more than 5°C (9°F) above their 1981–2010 averages. Cooler- and much-cooler-than-average conditions were observed across much of western Canada, most of eastern Europe, and a large swath extending across much of central Asia, where temperatures were more than 5°C (9°F) below their 1981–2010 averages in places. No land areas experienced record cold temperatures during October 2016. Africa as a whole observed its second warmest October on record, behind only 2015; North America had its seventh warmest; Asia had its 39th coolest October in the 107-year continental record. Image credit: NOAA National Centers for Environmental Information (NCEI).


As we blogged about on November 11, a weak La Niña event is now underway in the Eastern Pacific. The cool waters present in that region have helped cool the planet slightly below the record warm levels observed during the strong El Niño event of 2015 - 2016. The fact that October 2016 was still the 2nd to 3rd warmest October on record despite the presence of La Niña 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-October 2016) is an impressive 0.97°C (1.75°F) above the 20th-century average and 0.10°C (0.18°F) warmer than the previous January-to-October record, set in 2015 (see Figure 2 below). Remarkably, no land areas were cooler than average for the year-to-date. Barring an asteroid impact or the largest volcanic eruption in human history sometime in the next month, it is almost certain that 2016 will end up as the warmest year on record for the planet, giving us three consecutive warmest years on record.

Ocean-only, land-only, and lower atmosphere temperatures in October
Ocean-only temperatures this October were the second warmest on record, while land-only temperatures were the 16th warmest on record. (Since most of Earth’s surface is covered by ocean, the land-plus-ocean reading is dominated by the ocean-only temperatures, thus keeping October 2016 so warm globally.) Including 2016, the past five Octobers (2012–2016) have had the five highest October global ocean temperatures in the 137-year record. For the lowest 8 km of the atmosphere, global satellite-measured temperatures in October 2016 were the second warmest in the 38-year record, just behind October 2015, according to the University of Alabama in Huntsville (UAH). For the Jan - Oct year-to-date period, these temperatures have been the warmest on record.


Figure 2. Departure from the 20th-century average for the global January-through-October 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).

Arctic sea ice hits its lowest October extent on record
October 2016 Arctic sea ice extent was the lowest in the 38-year satellite record, according to the National Snow and Ice Data Center (NSIDC). The new record low was due, in large part, to high sea surface temperatures in open water areas and unusually high October air temperatures that extended from the surface through a considerable depth of the atmosphere. Amazingly, temperatures in the Arctic have spiked in mid-November to even higher values, and were 20°C (36°F) above average north of 80°N this week (see Figure 3). The unusual warmth in the Arctic has created an unusual amount of open water, which has provided high amounts of moisture to the atmosphere. As a result, widespread snows fell in regions where it was cold enough to snow; snow cover in the Northern Hemisphere in October was the third greatest on record.


Figure 3. Daily mean temperatures by Julian day over the Arctic north of 80°N, as compiled by the Danish Meteorological Institute (DMI). Temperatures for this year (red line) are compared to the long-term averages (green line.) This week’s heat spike to 20°C (36°F) above average is a greater deviation from average than any previous spike recorded at any time of year since DMI began tracking Arctic temperatures in 1956. Previous record: 17°C warmer than average, set in December 2002 and January 2006. Thanks go to WU member VibrantPlanet for pointing this out.

One billion-dollar weather disaster in October 2016: Hurricane Matthew
According to the October 2016 Catastrophe Report from insurance broker Aon Benfield, one billion-dollar weather-related disaster hit the planet in October: Hurricane Matthew, which tore through the Caribbean before pounding The Bahamas and the southeast United States. Matthew caused $5.5 billion in damage in the Caribbean and The Bahamas, and up to $10 billion in damage to the U.S. Two other tropical cyclones in October fell just short of being billion-dollar disasters: Super Typhoon Haima in the Philippines and China ($940 million in damage) and Super Typhoon Sarika in the Philippines and China ($890 million). From January through October 2016, there were 28 billion-dollar weather disasters globally. This is the fifth greatest number of such disasters in any year since 1990, with only 2013 (41), 2010 (40), 2011 (35) and 2014 (29) with more. For the U.S., Aon Benfield counted thirteen billion-dollar weather disasters during January - October 2016, which is the second highest number of such disasters on record since 1980 (the record: sixteen in 2011.)

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

1) Flooding, Yangtze Basin, China, 5/1 - 8/1, $28.0 billion, 475 killed
2) Hurricane Matthew, Caribbean, Bahamas, U.S., 9/28 - 10/10, $15 billion, 601 killed
3) Flooding, Louisiana U.S., 8/9 - 8/16, $10 - $15 Billion, 13 killed
4) Drought, China, 1/1 - 3/1, $6 billion, 0 killed
5) Flooding, Germany, France, Austria, Poland, 5/26 - 6/6, $5.5 billion, 17 killed
6) Drought, India, 1/1 - 6/30, $5.0 billion, 0 killed
7) Wildfire, Fort McMurray, Canada, 5/2- 6/1, $5.0 billion, 0 killed
8) Flooding, Northeast China 7/16 - 7/24, $4.7 billion, 289 killed
9) Severe Weather, Plains-Southeast U.S., 4/10 - 4/13, $4.3 billion, 1 killed
10) Severe Weather, Rockies-Plains-Southeast-Midwest U.S., 3/22 - 3/25, $2.5 billion, 0 killed
11) Super Typhoon Meranti, China, Taiwan, Philippines, 9/13 - 9/16, $2.5 billion, 44 killed
12) Flooding, China, 6/18 - 6/23, $2.3 billion, 68 killed
13) Flooding, Texas U.S., 4/15 - 4/19, $2.0 billion, 9 killed
14) Winter Weather, East Asia, 1/20 - 1/26, $2.0 billion, 116 killed
15) Severe Weather, Plains-Midwest U.S., 4/29 - 5/3, $1.8 billion, 6 killed
16) Tropical Cyclone Roanu, Sri Lanka, India, Bangladesh, Myanmar, China, 5/14 - 5/21, $1.8 billion, 135 killed
17) Severe Weather, Plains-Rockies U.S., 7/28 - 7/29, $1.6 billion, 0 killed
18) Drought, Zimbabwe, 6/1 - 8/10, $1.6 billion, 0 killed
19) Flooding and Severe Weather, Plains-Midwest-Southeast-Northeast U.S., 3/4 - 3/12, $1.5 billion, 6 killed
20) Super Typhoon Nepartak, Philippines, Taiwan, China, 7/8 - 7/9, $1.4 billion, 111 killed
21) Severe Weather, Plains-Southeast U.S., 3/17 - 3/18, $1.4 billion, 0 killed
22) Tropical Cyclone Winston, Fiji, 2/16 - 2/22, $1.4 billion, 44 killed
23) Flooding, Argentina and Uruguay, 4/4 - 4/10, $1.3 billion, 0 killed
24) Severe Weather, Plains-Midwest U.S., 5/21 - 5/28, $1.3 billion, 1 killed
25) Severe Weather, Plains-Midwest-Southeast-Northeast U.S., 2/22 - 2/25, $1.2 billion, 10 killed
26) Severe Weather, Netherlands, 6/23 - 6/24, $1.1 billion, 0 killed
27) Severe Weather, Plains-Midwest-Mississippi Valley U.S., 5/7 - 5/10, $1.0 billion, 2 killed
28) Winter Weather, Eastern U.S., 1/21 - 1/24, $1.0 billion, 58 killed

And here is the one billion-dollar disaster from October 2016 in more detail:


Disaster 1. Category 4 Hurricane Matthew devastated Haiti on October 4, killing 546, making it the Atlantic’s deadliest hurricane in 11 years. Damage in Haiti was estimated at $1.9 billion—a staggering 21% of the impoverished nation’s GDP, and by far Haiti’s costliest hurricane on record, according to the international disaster database, EM-DAT. The previous record was $400 million (1980 dollars) in damage wrought by Hurricane Allen. Matthew battered Cuba as a Category 4 storm, causing $2.6 billion in damage (3.2% of their GDP.) Matthew was Cuba’s second most expensive hurricane on record, behind Hurricane Georges of 1998 ($3 billion in damage in 2016 dollars, according to EM-DAT.) The Bahamas suffered $600 million in damage from Matthew (6.8% of GDP), making it their third most expensive hurricane on record behind Hurricane Frances of 2004 ($1.28 billion in losses, 2016 dollars) and Hurricane Jeanne of 2004 ($700 million in damage). Matthew grazed the coast of Florida and Georgia before making landfall in South Carolina on October 8 as a Category 1 hurricane with 75 mph winds. Matthew killed 49 people in the U.S., 28 of them in North Carolina. U.S. damage was estimated at up to $10 billion. This would make Matthew the 17th most expensive hurricane in U.S. history. Remnant moisture from Matthew also brought flooding rains and high winds to parts of the Maritime Provinces of Canada, causing tens of millions of dollars in damage. In this image, we see a small town along the southwestern coast of Haiti that suffered extreme storm surge damage from Hurricane Matthew. Image credit: United Nations Stabilization Mission in Haiti (MINUSTAH), via univision.com.

Notable global heat and cold marks set in October 2016
Hottest temperature in the Northern Hemisphere: 44.5°C (112.1°F) at Podor, Senegal, 9 October
Coldest temperature in the Northern Hemisphere: -41.4°C (-42.5°F) at Geo Summit, Greenland, 1 October
Hottest temperature in the Southern Hemisphere: 44.2°C (111.6°F) at Augrabies Falls, South Africa, 28 October
Coldest temperature in the Southern Hemisphere: -72.7°C (-98.9°F) at Vostok, Antarctica, 11 October
(Courtesy of Maximiliano Herrera.)

Major weather stations that set (not tied) new all-time heat or cold records in October 2016 (Courtesy of Maximiliano Herrera)
Macapa (Brazil) max. 36.6°C, 5 October
Bandarawela (Sri Lanka) max. 33.0°C, 11 October
Majuro (Marshall Islands) max. 34.0°C, 16 October
Taua (Brazil) max. 39.4°C, 19 October
Tshane (Botswana) max. 41.5°C, 31 October

Note: On 5 October Buffelsfontein Farm in South Africa recorded -10.5°C, which is the lowest temperature ever measured in Africa for the month of October.

No all-time national heat records set or tied in October 2016
No nations or territories set all-time heat or cold records in October 2016. From January through October 31, 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.) For a detailed list of these all-time records, see our September global climate summary post.

We'll be back with our next post on Friday. See our earlier post today for more on Invest 90L, in the southwest Caribbean, which has changed little since Wednesday.

Jeff Masters