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. (2016). Temperature anomalies for land and ocean are analyzed separately and then merged to form the global analysis. For more information, please visit NCEI'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.


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 May 2017 height and anomaly mapMay 2017 and March - May 2017 height and anomaly mapMarch–May 2017 maps—is generally reflected by areas of positive and negative temperature anomalies at the surface, respectively.

May

May 2017 was characterized by warmer- to much-warmer-than-average conditions across most of the world's land and ocean surfaces. However, near- to cooler-than-average conditions were present across the eastern half of the contiguous U.S., eastern Europe, western and north-central Russia, as well as parts of the northern and southern Atlantic Ocean, northern and southern Pacific Ocean, and the tropical Indian Ocean. Areas observing record warmth were sparse during May 2017, with the most notable warmth across northern Africa and southwest Asia near the Caspian Sea where temperature departures from average were +2.0°C (+3.6°F) to +3.0°C (+5.4°F). Parts of eastern Africa and the surrounding ocean off the coast of eastern Africa also had record warm temperatures during May 2017. No land or ocean areas had record cold temperatures. Averaged as a whole, the global land and ocean temperature for May 2017 was 0.83°C (1.49°F) above the 20th century average of 14.8°C (58.6°F) and the third highest May in the 138-year global records, behind 2016 (+0.89°C / +1.60°F) and 2015 (+0.86°C / +1.55°F). This was also the coolest monthly temperature departure from average since December 2016 (0.80°C / 1.44°F) and tied with April 2010, November 2013, and December 2014 as the 26th highest monthly global land and ocean temperature departure from average in the 1,649-monthly records. May 2017 also marks the 389th consecutive month with globally-average temperature nominally above the 20th century average. December 1984 was the last time a monthly temperature was below the 20th century average at -0.09°C (-0.16°F).

The global land-only surface temperature was the coolest May land temperature since 2011 and the seventh highest since global records began in 1880 at 1.15°C (2.07°F) above the 20th century average 11.1°C (52.0°F). According to NCEI's Regional Analysis, three of six continents had a top nine warm May, with Africa having its highest May temperature since continental records began in 1910. Meanwhile, May 2017 was North America's coolest May since 2013 and the 15th highest May temperature in the 107-year record. Europe's May 2017 temperature tied with 2014 as the 16th highest May temperature on record. Similarly, Oceania had its coolest May temperature since 2012 and the 20th highest May temperature on record.

Select national information is highlighted below. Please note that different countries report anomalies with respect to different base periods. The information provided here is based directly upon these data:

  • Spain's May 2017 national temperature of 19.0°C (66.2°F) was 2.4°C (4.3°F) above the 1981–2010 average and the second highest May temperature since 1965, behind the record year of 2015.
  • The May 2017 average temperature across the United Kingdom was 12.1°C (53.8°F) or 1.7°C (3.1°F) above the 1981–2010 average. This was the second highest May temperature since national temperature records began in 1910, behind 2008. Regionally, England, Wales, Scotland, and Northern Ireland had a top third warm May on record.
  • Near-average temperatures at the start of May were followed by summer-like temperatures by mid-month in France. According to Meteo France, several temperature records were broken as temperatures were similar to those typically observed during the summer month of July. Of note, Biscarosse set a new May temperature record when temperatures soared to 35.1°C (95.2°F) on May 25, besting the previous record of 34.2°C (93.6°F) set on 16 May 2002. On May 28, France had a national average daily temperature of 22.9°C (73.2°F), which is the highest temperature for any day in May in 70 years. France's May 2017 national temperature of 16.5°C (61.7°F) was 1.5°C (2.7°F) above the 1981–2010 average. This value was among the ten warmest Mays in the nation's 118-year record.
  • Unusually warm temperatures engulfed Portugal during May 2017. Portugal's national average mean temperature was 18.47°C (65.25°F) or 2.74°C (4.93°F) above average—the third highest May temperature since national records began in 1931, trailing behind 2011 and 2015. The nation's average maximum temperature was 24.96°C (76.93°F), which is 4.0°C (7.2°F) above average and the second highest May maximum temperature since 1931.
  • The Netherlands also experienced unusually warm conditions, with De Bilt recording an average temperature of 15.0°C (59.0°F). This was 1.9°C (3.4°F) above the 1981–2010 average of 13.1°C (55.6°F), resulting in the fourth highest May temperature since 1901.
  • Austria recorded a new May national maximum temperature on 30 May 2017, when temperatures reached 35.0°C (95.0°F) in Horn (Lower Austria). The previous national record was 34.9°C (94.8°F) set on 28 May 2008. The last time Austria observed temperatures above 33.0°C (91.4°F) in May was in 2005 and 2008. As a whole, Austria's May 2017 national temperature average was 1.1°C (2.0°F) above average and among the 25 warmest Mays since national records began in 1767.
  • In contrast, Finland had temperatures that were 1.0°C–3.0°C (1.8°F–5.4°F) below average across the country. According to the Finnish Meteorological Institute, the last time southern and central Finland saw similar cool conditions was in 1999, while for the northern part of the country it was in 1968.
  • Australia experienced above-average temperatures during May 2017, observing a national temperature departure from average of +0.71°C (+1.28°F). This was the 21st highest May temperature in the nation's 108-year record. Regionally, Queensland had its sixth highest May temperature on record. Maximum temperatures were unusually warm, with May 2017 tying as the ninth highest May maximum temperature for the nation as a whole. Regionally, Queensland, Western Australia, and the Northern Territory had a top seven warm maximum May temperature.

The average May temperature for the global oceans was 0.71°C (1.28°F) above the 20th century average of 16.3°C (61.3°F). This was the third highest May global ocean temperature in the 138-year record, trailing behind 2016 (+0.76°C / +1.37°F) and 2015 (+0.72°C / +1.30°F). ENSO-neutral conditions remained across the equatorial Pacific Ocean during May 2017. According to NOAA's Climate Prediction Center, ENSO-neutral conditions are favored through the Northern Hemisphere fall (Southern Hemisphere spring) 2017. This forecast focuses on the ocean surface temperatures between 5°N and 5°S latitude and 170°W to 120°W longitude, called the Niño 3.4 region.

May Ranks and Records
MayAnomalyRank
(out of 138 years)
Records
°C°FYear(s)°C°F
Global
Land+1.15 ± 0.12+2.07 ± 0.22Warmest7th2012+1.29+2.32
Coolest132nd1907-0.99-1.78
Ocean+0.71 ± 0.14+1.28 ± 0.25Warmest3rd2016+0.76+1.37
Coolest136th1911-0.54-0.97
Land and Ocean+0.83 ± 0.13+1.49 ± 0.23Warmest3rd2016+0.89+1.60
Coolest136th1911-0.48-0.86
Northern Hemisphere
Land+1.15 ± 0.11+2.07 ± 0.20Warmest8th2012+1.50+2.70
Coolest131st1907-1.06-1.91
Ocean+0.76 ± 0.14+1.37 ± 0.25Warmest3rd2015, 2016+0.84+1.51
Coolest136th1911-0.52-0.94
Land and Ocean+0.91 ± 0.13+1.64 ± 0.23Warmest3rd2015+1.02+1.84
Coolest136th1907-0.60-1.08
Southern Hemisphere
Land+1.16 ± 0.15+2.09 ± 0.27Warmest2nd2014+1.31+2.36
Coolest137th1917-1.26-2.27
Ocean+0.69 ± 0.15+1.24 ± 0.27Warmest2nd2016+0.71+1.28
Coolest137th1911-0.54-0.97
Land and Ocean+0.76 ± 0.14+1.37 ± 0.25Warmest2nd2016+0.77+1.39
Coolest137th1911-0.55-0.99
Arctic
Land and Ocean+0.68 ± 0.12+1.22 ± 0.22Warmest31st2010+2.05+3.69
Coolest108th1890-1.98-3.56

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

Seasonal (March–May)

Globally, the average land and ocean surface temperature for March–May 2017 was the second highest such period since global temperature records began in 1880 at 0.92°C (1.66°F) above the 20th century average of 13.7°C (56.7°F) and behind 2016 by 0.15°C (0.27°F). Spatially, much of the world's land and ocean surfaces observed warmer- to much-warmer-than-average conditions, with the most notable warm temperature departure from average across northern, central and eastern Asia, where temperatures were +3.0°C (5.4°F) or higher. Record warm temperatures across the land surfaces were present in central and eastern Asia, and parts of northern Africa. According to NCEI's Regional Analysis, four of six continents had a top seven warm March–May in the 107-year record, with Africa having its third highest March–May temperature on record.

The March–May 2017 seasonal global land surface temperature was the second highest on record for the season at 1.47°C (2.65°F) above the 20th century average of 8.1°C (46.4°F), behind 2016 by 0.37°C (0.67°F). Record warmth across the oceans was present mainly across parts of the Pacific Ocean and southwestern Indian Ocean. As a whole, the globally-average ocean surface temperature was 0.72°C (1.30°F) above the 20th century average of 16.1°C (61.0°F)—this was also the second highest March–May period since global records began in 1880, behind 2016 (+0.79°C / +1.42°F).

Select national information is highlighted below. (Please note that different countries report anomalies with respect to different base periods. The information provided here is based directly upon these data):

  • Warmer-than-average temperatures engulfed much of the United Kingdom during March–May 2017. Spring 2017 temperature for the nation was 9.1°C (°F), which is 1.4°C (°F) above the 1981–2010 average and the second highest March–May temperature in the 108-year record, behind 2011.
  • France's spring 2017 national temperature was 1.4°C (°F) above the 1981–2010 average, the third highest spring temperature since national records began in 1900, trailing behind 2011 (1.98°C / °F) and 2007 (1.58°C / °F).
  • De Bilt, Netherlands had an average temperature of 10.7°C (°F), which is 1.2°C (°F) above the 1981–2010 average of 9.5°C (°F). This was the fourth highest March–May period since national temperature records began in 1901.
  • Austria's national temperature during March–May 2017 was 1.5°C (°F) above the 1981–2010 average. Spring 2017 ranked among the ten warmest such periods in the nation's 251-year record. Regionally, there were several locations that had their top three warm springs on record: Lienz (warmest), Klagenfurt (second warmest), and the weather station at Graz University (third warmest).
March–May Ranks and Records
March–MayAnomalyRank
(out of 138 years)
Records
°C°FYear(s)°C°F
Global
Land+1.47 ± 0.12+2.65 ± 0.22Warmest2nd2016+1.84+3.31
Coolest137th1898-0.87-1.57
Ocean+0.72 ± 0.15+1.30 ± 0.27Warmest2nd2016+0.79+1.42
Coolest137th1911-0.53-0.95
Land and Ocean+0.92 ± 0.14+1.66 ± 0.25Warmest2nd2016+1.07+1.93
Coolest137th1911-0.52-0.94
Northern Hemisphere
Land+1.64 ± 0.15+2.95 ± 0.27Warmest2nd2016+2.04+3.67
Coolest137th1898-0.92-1.66
Ocean+0.75 ± 0.14+1.35 ± 0.25Warmest2nd2016+0.82+1.48
Coolest137th1911-0.49-0.88
Ties: 2015
Land and Ocean+1.09 ± 0.14+1.96 ± 0.25Warmest2nd2016+1.29+2.32
Coolest137th1909-0.56-1.01
Southern Hemisphere
Land+1.03 ± 0.14+1.85 ± 0.25Warmest5th2016+1.31+2.36
Coolest134th1917-0.98-1.76
Ties: 1998
Ocean+0.70 ± 0.16+1.26 ± 0.29Warmest2nd2016+0.77+1.39
Coolest137th1911-0.55-0.99
Land and Ocean+0.75 ± 0.15+1.35 ± 0.27Warmest2nd2016+0.85+1.53
Coolest137th1911-0.56-1.01
Arctic
Land and Ocean+2.15 ± 0.11+3.87 ± 0.20Warmest5th2016+2.55+4.59
Coolest134th1902-2.32-4.18

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

Year-to-date (January–May)

The globally-average temperature across land and ocean surfaces for January–May 2017 was 0.92°C (1.66°F) above the 20th century average of 13.1°C (55.5°F). This was the second highest January–May period in the 138-year record, falling behind the record year 2016 by 0.17°C (0.31°F). The first five months of the year were characterized by warmer- to much-warmer-than-average conditions across most of the land and ocean surfaces, with record warmth observed across eastern Russia, Mexico and surrounding area of the Gulf Coast, Madagascar and parts of the southwestern Indian Ocean, Hawaii and the surrounding Pacific Ocean, western tropical Pacific Ocean as well as parts of the southern parts of the Pacific Ocean, and sporadic across the eastern side of the Atlantic Ocean. Near- to cooler-than-average conditions were limited to parts of the northern Pacific Ocean, central and eastern Indian Ocean, and northern Atlantic Ocean south of Greenland. No land or ocean areas had record cold temperatures during January–May 2017. According to NCEI's Regional Analysis, five of six continents had a top eight warm January–May on record, with Africa having its fourth warmest January–May on record.

The year-to-date global land surface temperature was also the second highest on record at 1.54°C (2.77°F) above the 20th century average of 6.0°C (42.8°F), behind 2016 (+1.88°C / +3.38°F). The average global ocean surface temperature for January–May 2017 was also second highest on record at 0.70°C (1.26°F) above the 20th century average of 16.0°C (60.8°F). This value is 0.11°C (0.20°F) less than the record January–May 2016.

January–May Ranks and Records
January–MayAnomalyRank
(out of 138 years)
Records
°C°FYear(s)°C°F
Global
Land+1.54 ± 0.16+2.77 ± 0.29Warmest2nd2016+1.88+3.38
Coolest137th1893-0.99-1.78
Ocean+0.70 ± 0.16+1.26 ± 0.29Warmest2nd2016+0.81+1.46
Coolest137th1911-0.51-0.92
Land and Ocean+0.92 ± 0.16+1.66 ± 0.29Warmest2nd2016+1.09+1.96
Coolest137th1911-0.52-0.94
Northern Hemisphere
Land+1.74 ± 0.20+3.13 ± 0.36Warmest2nd2016+2.09+3.76
Coolest137th1893-1.14-2.05
Ocean+0.73 ± 0.16+1.31 ± 0.29Warmest2nd2016+0.86+1.55
Coolest137th1911-0.47-0.85
Land and Ocean+1.12 ± 0.17+2.02 ± 0.31Warmest2nd2016+1.33+2.39
Coolest137th1893-0.68-1.22
Southern Hemisphere
Land+1.02 ± 0.15+1.84 ± 0.27Warmest4th2016+1.33+2.39
Coolest135th1917-0.92-1.66
Ties: 1998
Ocean+0.68 ± 0.17+1.22 ± 0.31Warmest2nd2016+0.78+1.40
Coolest137th1911-0.53-0.95
Land and Ocean+0.73 ± 0.16+1.31 ± 0.29Warmest2nd2016+0.86+1.55
Coolest137th1911-0.55-0.99
Arctic
Land and Ocean+2.20 ± 0.24+3.96 ± 0.43Warmest2nd2016+2.88+5.18
Coolest137th1966-1.79-3.22

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

Precipitation

May

The maps below represent precipitation percent of normal (left, using a base period of 1961–1990) and precipitation percentiles (right, using the period of record) based on the GHCN dataset of land surface stations. As is typical, precipitation anomalies during May 2017 varied significantly around the world. May precipitation was generally drier than normal across the western half of the contiguous U.S., northern and southern parts of South America, northern and southern Africa, much of Australia, central and eastern Asia, and scattered across Europe. Wetter-than-normal conditions were notable across the eastern half of the contiguous U.S., southern South America (particularly the region encompassing northern Argentina, Paraguay, and Uruguay), Russia, and southern and southeastern Asia.

Select national information is highlighted below. (Please note that different countries report anomalies with respect to different base periods. The information provided here is based directly upon these data):

  • Across Spain, the western half of the nation experienced near to wetter-than-average conditions during the month, while the eastern half had drier- to much-drier-than-average conditions. Averaged as whole, Spain had an average precipitation total of 44 mm, which is 77% of normal precipitation of 61 mm.
  • Above-average precipitation fell across parts of northern Argentina, with some locations receiving twice their monthly normal average precipitation. According to Argentina's Servicio Nacional Meteorológico, precipitation totals were over 400 mm, causing floods and damages to the farming and cattle industry. In contrast, some parts in Patagonia experienced precipitation deficits.
  • Australia's May 2017 precipitation total was 15.6 mm, which is 45% below the 1961–1990 average and the 26th driest May in the nation's 118-year record.
  • Austria had its driest May since 2001, with a precipitation deficit of 40%.

Seasonal (March–May)

As is typical, precipitation anomalies during March–May 2017 varied significantly around the world. During March–May 2017, above-average seasonal precipitation was observed across much of the eastern half of the contiguous U.S. and the northwestern U.S., southern Argentina, eastern Europe, and northern Asia. Drier-than-average conditions were notable across the southwestern contiguous U.S., Alaska, northern and northeastern South America, central and western Europe, southern Australia, and parts of central, southern and eastern Asia.

References


Citing This Report

NOAA National Centers for Environmental Information, Monthly Global Climate Report for May 2017, published online June 2017, retrieved on March 28, 2024 from https://www.ncei.noaa.gov/access/monitoring/monthly-report/global/201705.