The monthly global land and ocean temperatures at the start of 2017 were extremely warm, with the first four months each ranking as the second warmest for their respective months, behind the record year 2016. Of particular note, the global land and ocean temperature for the month of March 2017 was 1.03°C (1.9°F) above the 20th century average—this marked the first time the monthly temperature departure from average surpassed 1.0°C (1.8°F) in the absence of an El Niño episode in the tropical Pacific Ocean. After reaching its peak monthly temperature departure from average in March, temperatures began to slowly decrease in magnitude, ranging between +0.73°C to +0.88°C (+1.31°F to +1.58°F). The last four months each ranked among the four warmest on record, giving way to 2017 becoming the third warmest year in NOAA's 138-year record. The 2017 average global temperature across land and ocean surface areas was 0.84°C (1.51°F) above the 20th century average of 13.9°C (57.0°F), behind the record year 2016 (+0.94°C / +1.69°F) and 2015 (+0.90°C / +1.62°F; second warmest year on record) both influenced by a strong El Niño episode. The year 2017 is also the warmest year without an El Niño present in the tropical Pacific Ocean.
2017 also marks the 41st consecutive year (since 1977) with global land and ocean temperatures at least nominally above the 20th century average, with the six warmest years on record occurring since 2010. Since the start of the 21st century, the global temperature has been broken five times, three of those being set back to back (2014–2016). The yearly global land and ocean temperature has increased at an average rate of 0.07°C (0.13°F) per decade since 1880; however, the average rate of increase is twice as great since 1980. From 1900 to 1980 a new temperature record was set on average every 13.5 years; however, since 1981 it has increased to every 3 years.
Ten Warmest Years (1880–2017)
The following table lists the global combined land and ocean annually-averaged temperature rank and anomaly for each of the 10 warmest years on record.
1 = Warmest
Period of Record: 1880–2017
|Year||Anomaly °C||Anomaly °F|
(out of 138 years)
|Land||+1.31 ± 0.15||+2.36 ± 0.27||Warmest||3rd||2016||+1.44||+2.59|
|Ocean||+0.67 ± 0.16||+1.21 ± 0.29||Warmest||3rd||2016||+0.76||+1.37|
|Land and Ocean||+0.84 ± 0.15||+1.51 ± 0.27||Warmest||3rd||2016||+0.94||+1.69|
|Land||+1.42 ± 0.17||+2.56 ± 0.31||Warmest||3rd||2016||+1.58||+2.84|
|Ocean||+0.79 ± 0.16||+1.42 ± 0.29||Warmest||3rd||2015||+0.89||+1.60|
|Land and Ocean||+1.03 ± 0.15||+1.85 ± 0.27||Warmest||3rd||2016||+1.13||+2.03|
|Land||+1.05 ± 0.12||+1.89 ± 0.22||Warmest||3rd||2015, 2016||+1.08||+1.94|
|Ocean||+0.58 ± 0.16||+1.04 ± 0.29||Warmest||3rd||2016||+0.69||+1.24|
|Land and Ocean||+0.66 ± 0.15||+1.19 ± 0.27||Warmest||3rd||2016||+0.75||+1.35|
The 1901–2000 average combined land and ocean annual temperature is 13.9°C (57.0°F), the annually averaged land temperature for the same period is 8.5°C (47.3°F), and the long-term annually averaged sea surface temperature is 16.1°C (60.9°F).
The following information was compiled from previous NCEI monitoring reports and public reports by National Hydrometeorological Services (NHMSs; peers of the U.S. National Weather Service), including those submitted to inform the Provisional Status of the Climate in 2017 by the World Meteorological Organization. More comprehensive information will be available in the WMO's final Statement, to be released in March 2018.
The year 2017 was characterized by warmer- to much-warmer-than-average conditions across much of the globe's land and ocean surfaces. Record warmth was observed across parts of the western and central Pacific Ocean, western Indian Ocean, southern South America, and the southwestern contiguous U.S. and scattered across parts of the northern Atlantic Ocean, Africa, the Middle East, and eastern Asia. Averaged separately, the global land surface temperature was 1.31°C (2.36°F) above the 20th century average and also the third highest in the 138-year record, behind 2016 (warmest) and 2015 (second warmest). The global oceans also had their third warmest year since global records began in 1880 at 0.67°C (1.21°F) above the 20th century average. Only the years 2016 and 2015 were warmer.
North America commenced the year with very warm conditions across much of the continent. The 2017 continental temperature for North America was the sixth highest yearly temperature on record.
- The contiguous U.S. had its third warmest year since national records began in 1895, behind 2012 (warmest) and 2016 (second warmest). The national 2017 temperature of 12.6°C (54.7°F) was 1.4°C (2.6°F) above the 1901–2000 average. 2017 marks the 21st consecutive year with above-average temperatures. The states of Arizona, Georgia, New Mexico, North Carolina, and South Carolina had their warmest year on record and an additional 32 states had a top 10 warm year.
- Warmer-than-average conditions engulfed much of Mexico throughout the year. Each month from January through October had a temperature departure greater than +1.0°C (+1.8°F) and ranked among the five highest on record, resulting in the highest January–October temperature since 1971. The January–October temperature of 23.3°C (73.9°F) was 1.8°C (3.2°F) above the 1981–2010 average. This value surpasses the previous record set in 2016 by 0.2°C (0.4°F).
South America had its second warmest year on record, trailing behind 2015 by 0.16°C (0.29°F).
- According to Argentina's Servicio Nacional de Meteorología, the nation's 2017 mean temperature was the highest since records began in 1961 at +0.66°C (+1.19°F) above average. This value surpasses the previous record set in 2012 by +0.03°C (+0.05°F).
- Chile had its second warmest summer (December 2016–February 2017) since national records began in 1964, with a temperature departure from average of +1.02°C (+1.84°F). Summer 1982/83 had the highest temperature on record at +1.13°C (+2.03°F) above average. Summer 2016/17 marked the sixth consecutive year with above-average temperatures for the nation. The month of January was exceptionally warm, recording a nationally-averaged maximum temperature of 33.3°C (91.9°F) or 3.2°C (5.8°F) above the 1981–2010 average—this was the warmest January since 1950.
Cold temperatures engulfed much of Europe at the start of 2017, with Austria experiencing one of its coldest Januarys since 1987, while the Netherlands had the coldest January since 2010. Then warmer temperatures affected the region throughout the rest of the year. Overall, Europe had its fifth highest temperature on record.
- Portugal had its second warmest year on record, with a national temperature departure from average of +1.1°C (2.0°F), behind the record year of 1997. National records began in 1931. The annual national maximum temperature was +2.4°C (+4.3°F) above the 1971–2000 average and the highest annual maximum temperature since 1931. This value surpassed the previous maximum temperature record set in 1997 by +1.02°C (+1.84°F). Meanwhile, the 2017 national minimum temperature was near average.
- Germany reported an annually-averaged temperature that was 9.6°C (49.3°F) or 0.7°C (1.3°F) above the 1981–2010 average. This value ranked among the eight warmest years since national records began in 1881.
- The United Kingdom's annually-averaged temperature of 9.6°C (49.3°F) was 0.7°C (1.3°F) above the 1981–2010 average and the fifth warmest year since national records began in 1910. The year was characterized by warmer-than-average conditions during much of the first half of the year, with the second half seeing temperatures closer to average. The months of February through June recorded monthly temperature departures from average that were greater than +1.0°C (+1.8°F).
- The year started off cooler-than-normal for France, warming up pretty quickly the rest of the year. In particular, the months of February, March, and June were much-warmer-than-average, with temperature departures from average above +2.0°C (+3.6°F). Of note, spring (March–May) and summer (June–August) 2017 ranked as the second warmest since national records began in 1900. Overall, the 2017 nationally-averaged temperature of 13.4°C (56.1°F) was 0.8°C (1.4°F) above the 1981–2010 average. This was the fifth highest yearly temperature on record.
- Although Austria commenced the year with its coldest January in three decades, it was followed by unusually warm months, including the warmest March and second warmest June on record. Summer (June–August) 2017 was the third warmest on record for the nation. Overall, the 2017 national temperature was 0.9°C (1.6°F) above the 1981–2010 average—the eighth warmest year since national records began in 1768.
Africa had its fourth highest continental temperature on record, behind 2010, 2016, and 2015.
Asia's 2017 regional temperature ranked as the third highest in the 108-year record, behind 2015 (highest) and 2007 (second highest).
- Much of the year was characterized by much-warmer-than-average conditions across much of Asia. Russia and China had their highest January–September temperature since national records began.
- Hong Kong experienced unusually warm conditions during 2017, having its warmest January, summer (June–August), and September on record. Averaged as a whole, the 2017 mean temperature for Hong Kong was 23.9°C (75.0°F) or 0.6°C (1.1°F) above the 1981–2010 average. 2017 ranked among the three warmest years since records began in 1884.
- The Kingdom of Bahrain's April 2017 mean temperature was 27.6°C (81.7°F), which is 2.6°C (4.7°F) above average. This was the highest mean temperature for April since national records began in 1902. The previous record was 27.4°C (81.3°F) set in 2000 and then again in 2014. The Kingdom of Bahrain also had its warmest July since national mean temperature records began in 1902, with a national temperature of 36.9°C (98.4°F) or 3.0°C (5.4°F) above average. This value exceeds the previous record set in 2012 and 2016 by 0.9°C (1.6°F). The August and September 2017 mean temperatures were each the highest for their respective months, surpassing their previous records by only 0.01°C (0.02°F).
Averaged as a whole, Oceania had its sixth warmest year since continental records began in 1910.
- New Zealand had its fifth warmest year on record, with a yearly temperature of 13.15°C (55.67°F), which is 0.54°C (0.97°F) above the 1981–2010 average. Only 2016, 2013, 1999, and 1998 were warmer than 2017.
- Much-warmer-than-average conditions engulfed much of Australia during 2017. The 2017 nationally-averaged mean temperature was the third warmest year since national records began in 1910, at 0.95°C (1.71°F) above the 1961–1990 average. Regionally, Queensland and New South Wales had their warmest year on record, while Victoria, Tasmania, and South Australia had a top ten warm year. The nation's annual maximum temperature departure from average of +1.27°C (+2.29°F) was the second highest on record, trailing behind 2013 by 0.18°C (0.32°F). The national minimum temperature was 11th highest on record at 0.62°C (1.12°F) above average. According to Australia's Bureau of Meteorology, seven of Australia's ten warmest years on record have occurred since 2005.
As indicated by the Global Percent of Normal Precipitation and Precipitation Percentiles maps below and as is typical, many stations were wet for the year, while many stations were dry. Also, as discussed below, extreme precipitation and drought events occurred across the world.
Drier-than-average conditions engulfed Portugal throughout most of 2017. The nationally-average total precipitation was 60% of Portugal's yearly precipitation normal, resulting in a rank among the top four driest years since 1931. The April–December period was the driest such period in the 87-year record.
March 2017 was a very wet month for the Dominican Republic. Climatologically, it is the island's driest month of the year. However, the nation's precipitation total was 96% above average. Several locations set new March precipitation records. Of note, La Unión, Puerto Plata had a monthly total of 608.7 mm (24.0 inches), which is a little over five times its normal March precipitation total of 116.3 mm (4.5 inches).
The 2017 precipitation total for Australia was 504.06 mm (19.8 inches) or 8% above the 1961–1990 average—the 30th wettest year since national precipitation records began in 1900. Much of the western half of Australia had above-average precipitation for the year, while the eastern half had drier-than-average conditions.
The year 2017 began wetter-than-average across parts of New Zealand, with several storms and cyclones producing heavy rains. Of note, Whangaparaoa, north of Auckland, received nearly five times its March normal total rainfall and had its wettest March since records began in 1946. Also, Cyclone Cook (April 6–11) caused torrential downpours, resulting in record or near-record precipitation totals. However, near the end of the year conditions switched from wet to dry across New Zealand, with several locations having their driest November on record. Of note, the town of Orari had no rainfall during November 2017—marking the first time since records began in 1897 that this location had zero rainfall for a whole month. Overall, the 2017 annual precipitation totals were below-average across most of Southland, interior Otago, and in the Southern Alps, while the rest of New Zealand had near- to above-average conditions. The town of Oamaru (located in the South Island) had its second wettest year on record, receiving a total of 813 mm (32.0 inches) of precipitation.
According to Environment and Climate Change Canada, drier-than-average conditions were present across northern and southwestern Ontario, with many locations receiving nearly one third of their monthly July precipitation total. However, wetter-than-average conditions were present across parts of northwestern, northeastern, and central Ontario, with eastern Ontario setting new high precipitation totals. Of note, Ottawa recorded a total of 250 mm (9.8 inches) of precipitation in July, tying with 1899 as the wettest July on record. Brockville had its third wettest July since 1871 and Cornwall its fourth wettest since 1951. Meanwhile, drier-than-average conditions plagued much of Western Canada during the year. The hardest hit areas included parts of British Columbia and the Prairies. The severe precipitation deficits in the province of British Columbia contributed to the development of the largest wildfire season (2.5 million acres of land affected) in the province's history.
An extratropical cyclone brought copious rain to parts of Argentina during the last week of March, setting several new daily and monthly precipitation records. The station Comodoro Rivadavia set a new 24-hour precipitation total record when it observed a total of 232.0 mm of rain on March 30. This surpassed the previous record of 48.3 mm set in 1976. Comodoro Rivadavia also set a new monthly record (320.4 mm), surpassing the previous record of 140.6 mm set in 1946.
Severe thunderstorms brought torrential rain to France's south-central department of Haute-Loire on June 13th, with several southern communes being the most affected. According to Meteo France, the Landos-Charbon station received a total of 123 mm (4.84 inches) of precipitation in one hour. To put it in perspective, this value represents 48 days of rain and is more than twice the 100-year return period. The total amount of precipitation for the event was 226 mm (8.90 inches) or nearly three months of rain.
Southern and western Finland had wetter-than-average conditions for October 2017, while northern parts of the country were drier-than-average. Of note, Nuuksio (a district of Espoo) had a total of 226.1 mm (8.9 inches) for October 2017, which is only 2 mm (0.08 inch) shy of tying the nation's record for the month, which was set in Hiiskula, Vihti in 2006.
According to the WMO's provisional statement, Thailand had its second wettest January–September period on record, while Italy had its driest January–September on record. Heavy precipitation during June 29–July 2 triggered severe floods across parts of southern China, causing 56 fatalities and over 5 billion USD in damages. In southern Asia, copious rain fell during August 9–12 across parts of Bangladesh, India, and Nepal. Several locations received their normal monthly precipitation totals in just a few days.
Hurricanes Irma and Maria affected the Caribbean and the southeastern U.S in September 2017. Maria caused great devastation and severe floods across Dominica, Puerto Rico, and the U.S. Virgin Islands. Maria was the strongest hurricane to impact Puerto Rico since Hurricane San Felipe II in 1928.
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