December 2015 Global Climate Report

December 2015 Selected Climate
Anomalies and Events Map

Introduction

Temperature anomalies and percentiles are shown on the gridded maps below. The anomaly map on the left is a product of a merged land surface temperature (Global Historical Climatology Network, GHCN) and sea surface temperature (ERSST.v4) anomaly analysis as described in Huang et al. (2015). Temperature anomalies for land and ocean are analyzed separately and then merged to form the global analysis. For more information, please visit NCDC's Global Surface Temperature Anomalies page. The percentile map on the right provides additional information by placing the temperature anomaly observed for a specific place and time period into historical perspective, showing how the most current month, season or year compares with the past.

The most current data for November be accessed via the Global Surface Temperature Anomalies page.

Supplemental November 2015 Information

• Resumen Global en Español
• Top 25 Monthly Temperature Departures
• 2015 Year-to-date Temperature versus Previous Years
• Monthly temperature anomalies versus El Niño

Temperatures

In the atmosphere, 500-millibar height pressure anomalies correlate well with temperatures at the Earth's surface. The average position of the upper-level ridges of high pressure and troughs of low pressure—depicted by positive and negative 500-millibar height anomalies on the December 2015 map—is generally reflected by areas of positive and negative temperature anomalies at the surface, respectively.

December

December 2015 Blended Land and Sea Surface
Temperature Anomalies in degrees Celsius

December 2015 Blended Land and Sea Surface
Temperature Percentiles

The December 2015 globally-averaged temperature across land and ocean surfaces was 1.11°C (2.00°F) above the 20^th century average of 12.2°C (54.0°F), the highest for any month since records began in 1880, surpassing the previous all-time record set two months ago in October by 0.12°C (0.21°F). This is the first time the global monthly departure from average has surpassed 1°C and is the largest margin by which an all-time monthly temperature record has been broken. Incredibly, the December 2015 temperature also surpasses the December record temperature set last year by 0.29°C (0.52°F), the largest margin by which a monthly temperature record has been broken for its respective month. And comparing to December 1997, the last December when a comparatively strong El Niño was in place, the December 2015 global temperature was 0.49°C (0.88°F) higher. Finally, this December also marks the eighth consecutive month (since April 2015) with a global monthly temperature breaking the record for its respective month.

Separately, the global land surface temperature was 1.89°C (3.40°F) above average, the highest on record for December, surpassing the previous record set in 2006 by 0.48°C (0.86°F). The Northern Hemisphere and Southern Hemisphere each had their record highest December land temperatures in the 136-year period of record. Across the globe, record warm temperatures were observed over every continent, including a large swath of eastern North America, southern Mexico through northern South America, western and central Europe, most of southern Africa, parts of central and southeastern Asia, and a large section of southeastern Australia. The highest temperature anomalies (more than 5°C / 9°F above the 1981–2010 average) were observed across much of northern Eurasia and eastern North America, driving much the global record warmth. It was cooler than average in eastern Russia, regions of central and northern Africa, and part of central South America, according to the December Land & Ocean Temperatures Departure from Average and Percentiles maps above. No land areas were record cold in December.

• Australia ended 2015 on a warm note, with its sixth highest December temperature in the country's 106-year period of record, at 1.04°C (1.87°F) higher than the 1961–1990 national average. With the contribution of a major heat wave during the third week of December in southeastern Australia, the states of Victoria, South Australia, and Tasmania were each record warm for the month. Overall, the warmth was due in large part to the average high minimum temperature, which was 1.25°C (2.25°F) above normal, the second highest on record, behind only 1972.
• The average temperature for Norway during December 2015 was 4.4°C (7.9°F) higher than the 1961–1990 average, marking the seventh warmest December since national records began in 1900. In eastern Norway, the monthly temperature was as much as 6.7°C (12.1°F) above average.
• Tropical air masses brought the United Kingdom its warmest December since records began in 1910, at 4.1°C (7.4°F) above the 1981–2010 national average and surpassing the previous record by a full 1.0°C (1.8°F). It was also the warmest December in the Central England temperature series, which dates back to 1659. In southern England, daily temperatures were 5–6°C (9–11°F) above average.
• France also observed its warmest December since its national records began in 1900, with a temperature almost 4°C (7°F) above the 1981–2010 average, easily surpassing the previous records of 1934 and 2000.
• With records dating to 1767, Austria reported its fourth warmest December, at 2.8°C (5.0°F) above the 1981–2010 average. It was the warmest December for the high Alpine regions of the country, with the average station temperature 6.6°C (11.9°F) above normal. For this region, it also marked the highest departure from average for any calendar month in the record.
• With a temperature 2.0°C (3.6°F) higher than the 1981–2010 average, Spain reported its second warmest December, behind only 1989, since national records began in 1961. The monthly maximum temperature was 2.8°C (5.0°F) above average, while the monthly minimum temperature was 1.1°C (2.0°F) above average for December. The anomalous warmth was observed across the country.
• With every province record warm, Germany as a whole observed its warmest December since national records began in 1881, with a temperature 5.2°C (9.4°F) higher than the 1981–2010 average. This surpassed the previous December records set in 1934 and 1974 by 0.8°C (1.4°F).
• The Netherlands also reported its warmest December in its 115-year period of record. The average monthly temperature of 9.9°C (49.1°F) was almost as high as the average temperatures in October and November 2015 (both 9.9°C / 49.8°F). The new December record easily surpassed the previous record from 1974 by 2.2°C (4.0°F).
• Russia was extremely warm in December. During the first 10 days of the month, temperatures were 12°–16°C (22°–29°F) above average. Overall, the Volga region had its warmest December on record and Central Russia had its second warmest.
• With 29 eastern states reporting record high temperatures for December, the continental U.S. as a whole was also record warm for the month, with a December temperature 3.3°C (6.0°F) above the 20^th century average.
• To the north, Ontario, Canada, was also record warm across the entire province for December, with temperatures 5°–10°C (9°–18°F) above the 1981–2010 average. These were the largest monthly departures from average among all months on record.

For the oceans, the globally-averaged temperature anomaly of +0.83°C (+1.49°F) was the highest on record for December, surpassing the previous record set in 2009 by 0.19°C (0.34°F). Near-record strong El Niño conditions prevailed in the central and eastern equatorial Pacific Ocean during the month. According to NOAA's Climate Prediction Center, as of early January 2016, the strong El Niño is expected to gradually weaken through spring 2016 and to transition to ENSO-neutral during late spring or early summer.

During December 2015, in addition to much of the eastern and central equatorial Pacific, the western North Atlantic, the North Indian Ocean, the ocean waters south of Australia, and parts of the Arctic Seas north of Europe were notably record warm. Parts of the northwestern Pacific, the North Atlantic south of Greenland, and regions in the southern oceans near Antarctica were were cooler or much cooler than average, with no areas of the global oceans record cold.

December Global Land and Ocean plot

December Global Hemisphere plot

Year-to-date (January–December)

January–December 2015 Blended Land and Sea Surface
Temperature Anomalies in degrees Celsius

January–December 2015 Blended Land and Sea Surface
Temperature Percentiles

The January–December map of temperature anomalies shows that warmer-than-average temperatures occurred across the vast majority of the globe during 2015, combining to bring overall record warmth for 2015, at 0.90°C (1.62°F) above the 20^th century average. This easily surpasses the previous record set just last year by 0.16°C (0.29°F). The global temperatures were strongly influenced by the strong El Niño conditions that developed during the year. The 2015 temperature also marks the largest margin by which an annual temperature record has been broken. Prior to this year, the largest margin occurred in 1998, when the annual temperature surpassed the record set in 1997 by 0.12°C (0.22°F). Incidentally, 1997 and 1998 were the last years in which a similarly strong El Niño was occurring. The annual temperature anomalies for 1997 and 1998 were 0.51°C (0.92°F) and 0.63°C (1.13°F), respectively, above the 20^th century average, both much lower than the 2015 temperature.

Please refer to the NCEI State of the Climate Annual Global Analysis report for more detailed information.

January–December Global Land and Ocean plot

January–December Global Hemisphere plot

The most current data may be accessed via the Global Surface Temperature Anomalies page.

Images of sea surface temperature conditions are available for all weeks during 2015 from the weekly SST page.

Precipitation

The maps below represent precipitation percent of normal (left) and precipitation percentiles (right) based on the GHCN dataset of land surface stations using a base period of 1961–1990. As is typical, precipitation anomalies during December 2015 varied significantly around the world. Precipitation was especially high across the eastern United States, Paraguay, and northwestern Europe. It was notably dry across northern Morocco and Algeria, South Africa, southern and eastern Europe, regions across northern South America, and eastern Brazil.

December 2015 Land-Only Precipitation
Percent of Normal

December 2015 Land-Only Precipitation Percentiles

• Norway was not only warm, but wet during December, receiving 150 percent of average precipitation overall. Parts of southern and western Norway received 300–400 percent of average precipitation for the month.
• The same held true for the United Kingdom, but on an even more notable scale. The UK's warmest December was accompanied not only its wettest December on record, but its wettest of any month in the record dating to 1910, with 191 percent of average rainfall. Hointers Pass in Cumbria received 341.4 mm (13.4 inches) of rain from 1800 GMT on the 4^th to 1800 GMT on the 5^th, marking the most precipitation ever recorded in the UK for any 24-hour period. In the west and north, a wet November and extremely heavy rain in December led to severe flooding in the region.
• In Austria, the warm December translated into a lack of snow. In Seefield, Tirol, no snow was recorded during December 2015. Seefield receives an average of 80 cm (31 inches) of snow during the month, with 26 days of snow cover, according to ZAMG.
• Dry conditions prevailed across Spain during December. On average, the country received just 20 percent (17 mm) of its normal monthly precipitation. Large regions across the eastern third of Spain and the Balearic Islands had no rain. For many areas, it was the driest December on record.
• Similar to the United Kingdom, the continental U.S. was both record warm and record wet for December, receiving 167 percent of average precipitation for the month. December 2015 marks the only month in the historical record with a month that was both record warm and record wet.

References

• Peterson, T.C. and R.S. Vose, 1997: An Overview of the Global Historical Climatology Network Database. Bull. Amer. Meteorol. Soc., 78, 2837-2849.
• Huang, B., V.F. Banzon, E. Freeman, J. Lawrimore, W. Liu, T.C. Peterson, T.M. Smith, P.W. Thorne, S.D. Woodruff, and H-M. Zhang, 2015: Extended Reconstructed Sea Surface Temperature Version 4 (ERSST.v4). Part I: Upgrades and Intercomparisons. J. Climate, 28, 911-930.

Citing This Report

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