July 2017 Global Climate Report

July 2017 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. (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 July 2017 map—is generally reflected by areas of positive and negative temperature anomalies at the surface, respectively.

July

July 2017 Blended Land and Sea Surface
Temperature Anomalies in degrees Celsius

July 2017 Blended Land and Sea Surface
Temperature Percentiles

The average global land and ocean surface temperature for July 2017 was the second highest for the month at 0.83°C (1.49°F) above the 20th century average of 15.8°C (60.4°F), behind the record year 2016 by 0.05°C (0.09°F). Nine of the 10 warmest Julys on record have occurred during the 21st century (since 2005), with only one year from the 20th century (1998) among the top 10 warmest Julys on record. July 2017 also marks the 41st consecutive July and the 391st consecutive month with a global temperature at least nominally above the 20th century average.

During July 2017, warmer-than-average temperatures were present across much of the land and ocean surfaces, with the most notable warm temperature departures from average across the western contiguous U.S., southern South America, the Middle East, Mongolia, China, and much of Australia, where departures from average were +2.0°C (+3.6°F) or greater. Record warmth was present across the southern half of Africa, the Middle East, northern and central Australia, and across parts of China, Mongolia, and Madagascar. Across the oceans, record warmth was widespread across the western Indian Ocean and scattered across the western and central Pacific Ocean, northwestern Atlantic Ocean (off the U.S. eastern coast), and the Barents Sea. Meanwhile, near to cooler-than-average conditions were present across much of Russia, eastern Canada, south-central Asia, the northern Pacific Ocean, the North Atlantic Ocean, and across parts of the southern oceans. The most notable cool temperature departure from average was observed across northeastern Russia, where temperatures were -2.0°C (-3.6°F) or lower. No land or ocean areas had record cold July temperatures. Regionally, five of six continents had a top seven warm July, with Africa and Oceania experiencing their warmest July since continental records began in 1910. Meanwhile, Europe had its smallest temperature departure from average since 2011 and the 17th highest July temperature in the 108-year continental record.

The July 2017 global land temperature was 1.20°C (2.16°F) above the 20th century average of 14.3°C (57.8°F) and the highest July land temperature in the 138-year record. This value surpasses the previous record set in 2016 by 0.07°C (0.13°F). The global ocean temperature was third highest on record at 0.69°C (1.24°F) above the 20th century average of 16.4°C (61.5°F), behind 2016 (+0.78°C / +1.40°F) and 2015 (+0.75°C / +1.35°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:

• The Kingdom of Bahrain 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). Daytime (maximum) and nighttime (minimum) temperatures were also much above average. The national mean maximum temperature was 42.1°C (107.8°F), which is 4.1°C (7.4°F) above average and the highest mean maximum temperature since maximum and minimum temperature records began in 1946, surpassing the previous record set in 2002 by 0.7°C (1.3°F). Minimum temperatures for July 2017 tied with 2010 and 2015 as the third highest since 1946 with a national temperature of 32.6°C (90.7°F), behind 2016 (33.2°C / 91.8°F) and 2014 (32.7°C / 90.9°F).
• Portugal's July 2017 national average temperature was warmer than average at +0.56°C (+1.01°F). The daytime (maximum) temperature was also warmer than average at 30.22°C (86.40°F) or 1.5°C (2.7°F) above average and the 11th highest July maximum temperature since 1931. Meanwhile, nighttime (minimum) temperatures were below average at 15.26°C (59.41°F) or 0.4°C (0.7°F) below average. According to the Portuguese Institute for Sea and Atmosphere, over 80% of Portugal's stations observed maximum temperatures greater or equal to 30.0°C (86.0°F) during July 2–4 and July 12–17, with 50% of stations recording maximum temperatures greater or equal to 35.0°C (95.0°F).
• Australia had its highest July mean temperature since 1975 and the third highest in the nation's 108-year record, with a mean temperature departure from average of 1.81°C (3.26°F) above the 1961–1990 average. The high mean temperature value was mainly driven by record warm maximum (daytime) temperature. The nation's maximum temperature for July 2017 was 2.62°C (4.72°F) above average, besting the previous record of +1.96°C (+3.53°F) set in 1975 by 0.66°C (1.19°F). The national minimum (nighttime) temperature was also above average at 1.0°C (1.8°F) above average and the 13th highest on record. Regionally, Queensland and the Northern Territory had their highest mean temperature on record, while South Australia and Western Australia had a top five warm mean temperature for July. Meanwhile, Queensland, Western Australia, and the Northern Territory had their highest maximum July temperatures on record, with New South Wales, Victoria, and South Australia having a top six warm maximum temperature on record for July 2017. Much of the nation had above-average minimum temperatures, with the exception of Victoria, Tasmania, and New South Wales. New South Wales had its lowest July minimum temperature since 2002 at -0.44°C (-0.79°F) below the 1961–1990 average.
• New Zealand's national July 2017 temperature was near average at 7.9°C (46.2°F) or 0.1°C (0.2°F) above the 1981–2010 average. Even though the national average was near average, the districts of Hurunui, Mackenzie, Waitaki, Dunedin, and Clutha experienced below-average temperatures (-0.51°C to -1.20°C / -0.92°F to -2.16°F) during the month. Several locations saw new low records or near-records for the month.

ENSO-neutral conditions continued to be present across the equatorial Pacific Ocean during July 2017. According to NOAA's Climate Prediction Center, ENSO-neutral is favored through the Northern Hemisphere winter (Southern Hemisphere summer) 2017–18. 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.

July Global Land and Ocean plot

July Global Hemisphere plot

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

Year-to-date (January–July)

January–July 2017 Blended Land and Sea Surface
Temperature Anomalies in degrees Celsius

January–July 2017 Blended Land and Sea Surface
Temperature Percentiles

The first seven months of the year were characterized by warmer to much-warmer-than-average conditions across much of the world's surface. The most notable warm anomalies were observed across much of central and eastern Asia, where temperature departures from average were +1.5°C (+2.7°F) or greater. Record warmth was present across western Europe, eastern Russia, western Mongolia, the Korean Peninsula, eastern and northern China, parts of eastern Africa, Madagascar, and scattered across the southeastern contiguous U.S., Mexico, and southern South America. Across the oceans, record warmth was observed across the western, central, and eastern Pacific Ocean, eastern Indian Ocean, and scattered across parts of the Gulf of Mexico and eastern Atlantic Ocean, off the western coast of Europe. No land or ocean areas had record cold July temperatures. Averaged as a whole, the January–July 2017 global land and ocean temperature was the second warmest such period on record, at 0.90°C (1.62°F) above the 20th century average of 13.8°C (56.9°F). This value falls behind the record year 2016 by 0.14°C (0.25°F), but is ahead of 2015 (now third warmest such period) by 0.04°C (0.07°F).

The January–July 2017 global land surface temperature was 1.45°C (2.61°F) above the 20th century average of 8.3°C (46.8°F) and the second highest temperature for January–July period in the 138-year record, behind the record year 2016 by 0.25°C (0.45°F). The January–July 2017 global ocean surface temperature was also second highest on record at 0.69°C (1.24°F) above the 20th century average of 16.1°C (61.0°F), trailing behind 2016 by 0.11°C (0.20°F).

According to NCEI's Regional Analysis, all six continents had a top nine warm January–July period, with South America experiencing its second highest January–July temperature, behind 2015.

January–July Global Land and Ocean plot

January–July Global Hemisphere plot

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

Precipitation

July

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 July 2017 varied significantly around the world. July 2017 precipitation was generally drier than normal across the northwestern contiguous U.S., Brazil, Paraguay, southern Argentina, central and southern Chile, central Asia, and southern Japan. Meanwhile, wetter-than-normal conditions were notable across the eastern half of the contiguous U.S., Alaska, northern Argentina, Uruguay, northern parts of Europe, central Russia, northwestern India, northern Japan, and across parts of China.

July 2017 Land-Only Precipitation
Percent of Normal

July 2017 Land-Only Precipitation Percentiles

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):

• According to the Portuguese Institute for Sea and Atmosphere, drier-than-average conditions plagued Portugal during July 2017, receiving 5.3 mm (0.21 inch) or 38% of July's normal precipitation. By the end of the month, much of the nation was experiencing drought conditions, with 70% of the country under severe drought and 9.6% having extreme drought.
• Australia experienced drier-than-average conditions during July 2017, with a national precipitation total of 13.5 mm (0.5 inch) or 61% of July's normal precipitation. Regionally, New South Wales had its driest July since 2002 and the eighth driest in the 118-year record, receiving only 29% of its July precipitation total. Meanwhile, the Northern Territory was the only region having wetter-than-average conditions. Several locations in the Northern Territory set new rainfall records for the month.
• Wetter-than-average conditions were present across much of New Zealand during July 2017, with several locations receiving more than double their monthly precipitation total. The above-average precipitation during the month was driven by several events impacting the region, including persistent heavy rain on July 21, which caused severe floods. The town of Oamaru, located in the South Island, had its wettest July on record, with 224 mm (8.8 inches) of precipitation or 553% of normal precipitation during July 2017. This value is the second-wettest month since records began in 1941, behind May 2010 (298 mm / 11.7 inches).
• According to the 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 and its fourth wettest since 1951.
• Fiji experienced below-average conditions during July 2017. According to Fiji's Meteorological Service, 21 of 23 stations observed below to much-below-average rainfall during the month, with only two stations having near to above-average conditions.
• Most of Ireland's stations had above-average July precipitation totals. The station located at Shannon Airport, Co Clare recorded double its monthly precipitation total (203%), resulting in its wettest July since 1946. Also of note, the station at Newport, Co Mayo had its wettest July since 2009, receiving 163% of its monthly normal precipitation.

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, 2016: Extended Reconstructed Sea Surface Temperature Version 4 (ERSST.v4). Part I: Upgrades and Intercomparisons. J. Climate, 28, 911-930.

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