Second Warmest January on Record Globally

January 2015 was the second warmest January since record keeping began in 1880, said NOAA's National Climatic Data Center (NCDC) on Thursday. NASA also rated January 2015 as the 2nd warmest January on record, behind January 2007, which had the warmest departure from average of any month in recorded history. January 2015's near-record warmth continues a trend of very warm months for the planet--December 2014 was the warmest December on record, and 2014 was Earth's warmest calendar year on record. Global ocean temperatures during January 2015 were the 3rd warmest on record, and global land temperatures were the 2nd warmest on record. Global satellite-measured temperatures in January 2015 for the lowest 8 km of the atmosphere were the 7th or 5th warmest in the 37-year record, according to Remote Sensing Systems and the University of Alabama Huntsville (UAH), respectively.


Figure 1. Departure of temperature from average for January 2015, the 2nd warmest January for the globe since record keeping began in 1880. China had its warmest January on record, and record warmth was observed over much of the Caribbean and portions of Brazil and Mongolia. Image credit: National Climatic Data Center (NCDC) .

No billion-dollar weather disasters in January 2015
No billion-dollar weather-related disasters hit the Earth during January 2015, according to the January 2015 Catastrophe Report from insurance broker Aon Benfield. January 2015 joins November 2014 as the only months since January 2012 to go without a billion-dollar weather disaster. However, one nation experienced its most expensive natural disaster in its history in January 2015: Malawi, where two weeks of heavy rains triggered rampaging floods that killed at least 176 people and left 260,000 homeless. According to EM-DAT, the international disaster database, the floods of March 10, 1991 were the most expensive weather-related natural disaster in their history, with damages estimated at $24 million (1991 dollars.) The floods of 2015 may be ten times more expensive: Malawi requested humanitarian assistance of $430 million for recovery efforts from last month's disaster. The tropical disturbance that spawned these heavy rains moved over Mozambique on January 14, triggering flooding that killed at least 120 people there. The next day, the disturbance moved over the Mozambique Channel between Mozambique and Madagascar, becoming Tropical Storm Chedza, which hit Madagascar on January 16, killing 68 people on the island.


Figure 2. A bridge destroyed by flooding at Nchalo in Chikwawa, Malawi, the week of January 13, 2015. Image credit: Source: Department of Disaster Management Affairs, Malawi.

No official El Niño, but unusual warmth in Eastern Pacific
January 2015 officially featured neutral El Niño conditions in the equatorial Eastern Pacific, but sea surface temperatures were 0.5°C above average in the so-called Niño3.4 region (5°S - 5°N, 120°W - 170°W), where SSTs must be at least 0.5°C above average for five consecutive months (each month being a 3-month average) for an El Niño event to be declared. The warmth in the Niño3.4 region has continued into mid-February, and was still standing at 0.5°C above average this week. NOAA is continuing its El Niño Watch, giving a 50 - 60% chance of a weak El Niño event verifying for late winter and early spring. Nearly all international computer models are now projecting Niño3.4 temperatures to be well above the 0.5°C threshold by July, according to a roundup released this week by the Australian Bureau of Meteorology. However, model predictions are least likely to be accurate when issued during the period from February to May, as temperature contrasts across the tropical Pacific are normally weakening at that point.

Arctic sea ice falls to 3rd lowest January extent on record
Arctic sea ice extent during January 2015 was the 3rd lowest in the 36-year satellite record, according to the National Snow and Ice Data Center (NSIDC). During most of January, the Arctic Oscillation (AO) was in a strongly positive phase, bringing low sea level pressure to the Arctic and high pressure to the middle latitudes of the Northern Hemisphere. Typically, during the positive phase of the AO, surface winds push ice away from the shores of Siberia, leading to the formation of more young, thin ice that is prone to melting out in summer. The positive phase also tends to increase the transport of thick, multiyear ice out of the Arctic through Fram Strait. Thus, January's weather may be setting the stage for greater ice melt in the Arctic during the summer of 2015 than occurred in 2014.

Notable global heat and cold marks set for January 2015
Hottest temperature in the Southern Hemisphere: 49.0°C (120.2°F) at Marble Bar, Australia, January 23
Coldest temperature in the Southern Hemisphere: -48.2°C (-54.8°F) at Concordia, Antarctica, January 31
Hottest temperature in the Northern Hemisphere: 42.0°C (107.6°F) at Abu Na'Ama, Sudan, January 30
Coldest temperature in the Northern Hemisphere: -55.0°C (-67.0°F) at Selagoncy, Russia, January 5

Major stations that set new all-time heat or cold records set in January 2015
Cozzo Spadaro (Italy): min. -0.2°C [31.6°F), January 1
Ottosdal (South Africa): max. 40.0°C [104°F], January 6
M'Pouya (Congo-Brazzaville): min. 12.5°C [54.5°F], January 12
Afiamalu (Samoa): max. 31.2°C [88.2°F], January 15
Jabal Shamas (Oman): min. -9.7°C [14.5°F], January 20
Paynes Find (Australia): max. 48.0°C [118.4°F], January 21
Lamap Malekula (Vanuatu): max. 34.5°C [94.1°F], January 22

New all-time national and territorial heat records set or tied in 2015
Futuna Airport (Wallis and Futuna Territory, France) hit 35.5°C (95.9°F) on January 19

Samoa tied its national heat record with 36.5°C (97.7°F) on 20 January at Asau. Previously, the record was set at the same location in December 1977.

A big thanks goes to Maximiliano Herrera for providing the global heat and cold records. He maintains a comprehensive list of extreme temperature records for every nation in the world on his website.

Jeff Masters