September 2019 Selected Climate Anomalies and Events Map

Introduction

PLEASE NOTE: With the May 2019 global report and data release, the National Centers for Environmental Information transitioned to an improved version of NOAA's Global Temperature data set (NOAAGlobalTemp version 5), which includes the updated versions of its global land (GHCNm version 4.0.1) and ocean (ERSST version 5) data sets. Please note that anomalies and ranks reflect the historical record according to these updated versions. Historical months and years may differ from what was reported in previous years. Please visit our Commonly Asked Questions for additional information.

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 version 5) anomaly analysis. 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.


Temperature

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 September 2019 map—is generally reflected by areas of positive and negative temperature anomalies at the surface, respectively.

September Temperature

The average global land and ocean surface temperature for September 2019 was 0.95°C (1.71°F) above the 20th century average and tied 2015 as the highest September temperature departure from average since global records began in 1880. Septembers of 2015, 2016, and 2019 were the only Septembers with a global land and ocean surface temperature departure from average of 0.90°C (1.62°F) or higher. September 2019 also tied with September 2015 and June 2019 as the 14th highest monthly temperature departure on record. March 2016 temperature departure of +1.31°C (+2.36°F) is the record warm month. This was also the 43rd consecutive September and the 417th consecutive month with temperatures, at least nominally, above the 20th century average.

Global Land and Ocean Temperature Anomalies for September

The Northern Hemisphere, as a whole, also had its warmest September on record at +1.24°C (2.23°F) above the 20th century average, surpassing the previous record set in 2016 by +0.03°C (+0.05°F). The five warmest Northern Hemisphere land and ocean surface temperature have occurred since 2015. Compared to all months, the Northern Hemisphere's September temperature departure tied with November 2015 as the 11th warmest monthly land and ocean temperature departure since monthly records began in 1880. The Southern Hemisphere land and ocean surface temperature was 0.64°C (1.15°F) above average and the seventh warmest on record. This was also the Southern Hemisphere's least warm September since 2013 and, compared to all months, the least warm monthly temperature departure since August 2018.

The global land-only surface temperature departure from average for September was +1.42°C (+2.56°F)—the warmest September on record. This value exceeds the previous record in 2016 by 0.04°C (0.07°F). The September 2019 global ocean-only surface temperature tied with 2016 as the second highest on record at 0.78°C (1.40°F) above average, trailing behind 2015 (+0.85°C / +1.51°F). Compared to all months, the global ocean-only temperature departure tied with July 2017 and September 2016 as the 18th highest monthly temperature departure in the 1,677 monthly record.

September 2019 was characterized by warmer-than-average conditions across much of the world's land and ocean surfaces. The most notable warm temperature departures from average were observed across much of Alaska, western Canada, the southern and southeastern contiguous U.S, the North Pacific Ocean as well as the Bering and Barents seas, central South America, Mongolia, and northern Russia, where temperatures were at least 2.0°C (3.6°F) or higher. Record warm temperatures were observed across parts of the North and Western Pacific Ocean, the Barents Sea, the south-central contiguous U.S., the Atlantic and Indian oceans, the Middle East, Mongolia and northern China, and Africa. Near- to cooler-than-average temperatures were limited to parts of Indonesia, northern Australia, western Asia, the eastern tropical Pacific Ocean, and across the South Indian Ocean. However, no land or ocean areas had a record-cold September.

Regionally, North America, South America, Africa, Asia, the Gulf of Mexico, and the Hawaiian region had a September temperature that ranked among the three highest for September on record. Of note, North America had its warmest September since continental records began in 1910 at 1.72°C (3.10°F) and surpassing the now second warmest September set in 1998 by 0.01°C (-0.02°F). September 2019 marked North America's 23rd consecutive September with temperatures, at least nominally, above average. The Gulf of Mexico also had its warmest September on record at 0.99°C (1.78°F) above average, respectively. This was 0.04°C (0.07°F) higher than the previous record set in 2016. Europe and the Caribbean region had a top eight warm September on record.

September Ranks and Records
SeptemberAnomalyRank
(out of 140 years)
Records
°C°FYear(s)°C°F
Global
Land+1.42 ± 0.26+2.56 ± 0.47Warmest1st2019+1.42+2.56
Coolest140th1884-0.78-1.40
Ocean+0.78 ± 0.14+1.40 ± 0.25Warmest2nd2015+0.84+1.51
Coolest139th1903, 1904, 1908-0.47-0.85
Ties: 2016
Land and Ocean+0.95 ± 0.15+1.71 ± 0.27Warmest1st2015, 2019+0.95+1.71
Coolest140th1912-0.53-0.95
Ties: 2015
Northern Hemisphere
Land+1.49 ± 0.18+2.68 ± 0.32Warmest2nd2016+1.60+2.88
Coolest139th1884-0.93-1.67
Ocean+1.10 ± 0.14+1.98 ± 0.25Warmest2nd2015+1.12+2.02
Coolest139th1912-0.61-1.10
Land and Ocean+1.24 ± 0.15+2.23 ± 0.27Warmest1st2019+1.24+2.23
Coolest140th1912-0.73-1.31
Southern Hemisphere
Land+1.26 ± 0.18+2.27 ± 0.32Warmest3rd2014+1.43+2.57
Coolest138th1891-0.76-1.37
Ties: 2013
Ocean+0.52 ± 0.15+0.94 ± 0.27Warmest8th2016+0.62+1.12
Coolest133rd1903-0.46-0.83
Ties: 2009
Land and Ocean+0.64 ± 0.16+1.15 ± 0.29Warmest7th2015, 2017, 2018+0.69+1.24
Coolest134th1911-0.49-0.88
Arctic
Land and Ocean+1.74 ± 0.21+3.13 ± 0.38Warmest2nd2016+1.93+3.47
Coolest139th1992-1.00-1.80

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

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:

  • Hong Kong's September 2019 mean temperature was 28.7°C (83.7°F) or 1.0°C (1.8°F) above the 1981–2010 average and was the seventh highest for September on record. According to Hong Kong's Observatory, Hong Kong had a total of seven consecutive days of hot nights during September 8–14, resulting in the longest streak of hot days on record for September. So far for the year, Hong Kong has had 45 hot nights, which is 27.2 above average and the highest number since 1884. The Hong Kong Observatory define hot nights as minimum (nighttime) temperatures ≥ 28.0°C (82.4°F).
  • Australia's mean temperature for September 2019 was 1.19°C (2.14°F) above the 1961–1990 average and the 19th warmest September in the nation's 110-year temperature record. The nation's maximum temperature was the fourth highest on record at 2.22°C (4.00°F) above average. Regionally, Western Australia had its highest maximum temperature (+2.81°C / +5.06°F) and its fourth highest mean temperature on record (+1.63°C / +2.93°F). New South Wales and South Australia had a September maximum temperature that ranked among the top seven warm Septembers on record.

ENSO-neutral conditions persisted during September 2019. According to NOAA's Climate Prediction Center, ENSO-neutral is favored during the Northern Hemisphere fall (Southern Hemisphere spring) 2019 through the Northern Hemisphere spring (Southern Hemisphere fall) 2020. 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.

Year-to-date Temperature

Each of the first nine months of the year had a global land and ocean temperature departure from average that ranked among the five warmest for their respective months. This gave way to the second warmest January–September in the 140-year record at 0.94°C (1.69°F) above the 20th century average. This was 0.12°C (0.22°F) cooler than the record warm such period set in 2016 and only 0.01°C (0.02°F) warmer than the now third warmest January–September set in 2017.

Global Land and Ocean Temperature Anomalies for January-September

The Northern Hemisphere land and ocean surface temperature tied with 2017 as the second highest January–September on record at 1.13°C (2.03°F) above average. Only January–September of 2016 was warmer (+1.31°C / +2.36°F). The Southern Hemisphere's January–September 2019 land and ocean surface temperature was 0.75°C (1.35°F) above average and also the second warmest such period on record, behind 2016 by 0.06°C (0.11°F).

The global land-only surface temperature of 1.41°C (2.54°F) above average was the third highest such period on record, following 2016 (+1.68°C / +3.02°F) and 2017 (+1.45°C / +2.61°F). The global ocean-only surface temperature departure was +0.77°C (+1.39°F)—the second highest January–September in the 140-year record. Only January–September 2016 was warmer at +0.83°C (+1.49°F).

Regionally, South America, Africa, and Oceania had their third warmest January–September on record. Europe, Asia, the Gulf of Mexico, and the Hawaiian region had their fourth warmest such period in the 110-year regional record. North America had its 15th warmest such period on record.

Much of the global land and ocean surface temperature was warmer than average during the first nine months of the year. The most notable warm temperature departures from average were present across much of Alaska, western Canada, and central Russia, where temperatures were at least +1.5°C (+2.7°F) above average. Record warm January–September temperatures for 2019 were observed across much of the southern half of Africa, the western Indian Ocean, Madagascar, and across parts of Australia, the western Pacific Ocean, New Zealand, Asia, the Atlantic Ocean, and North and South America. Near- to cooler-than-average conditions was limited to parts of central North America, the southeastern Pacific Ocean, the North Atlantic Ocean, Indonesia, and southeastern Indian Ocean. However, no land or ocean area had record cold year-to-date temperatures departures from average.

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:

  • Australia had its second warmest January–September in the nation's 110-year record.

January–September Ranks and Records
January–SeptemberAnomalyRank
(out of 140 years)
Records
°C°FYear(s)°C°F
Global
Land+1.41 ± 0.18+2.54 ± 0.32Warmest3rd2016+1.68+3.02
Coolest138th1884-0.73-1.31
Ocean+0.77 ± 0.18+1.39 ± 0.32Warmest2nd2016+0.83+1.49
Coolest139th1904, 1911-0.49-0.88
Land and Ocean+0.94 ± 0.17+1.69 ± 0.31Warmest2nd2016+1.06+1.91
Coolest139th1904, 1911-0.51-0.92
Northern Hemisphere
Land+1.46 ± 0.20+2.63 ± 0.36Warmest3rd2016+1.87+3.37
Coolest138th1884-0.83-1.49
Ties: 2015
Ocean+0.93 ± 0.17+1.67 ± 0.31Warmest2nd2016+0.96+1.73
Coolest139th1904-0.53-0.95
Land and Ocean+1.13 ± 0.18+2.03 ± 0.32Warmest2nd2016+1.31+2.36
Coolest139th1904-0.55-0.99
Ties: 2017
Southern Hemisphere
Land+1.29 ± 0.14+2.32 ± 0.25Warmest1st2019+1.29+2.32
Coolest140th1917-0.77-1.39
Ocean+0.64 ± 0.18+1.15 ± 0.32Warmest3rd2016+0.73+1.31
Coolest138th1911-0.49-0.88
Land and Ocean+0.75 ± 0.18+1.35 ± 0.32Warmest2nd2016+0.81+1.46
Coolest139th1911-0.52-0.94
Arctic
Land and Ocean+2.18 ± 0.21+3.92 ± 0.38Warmest2nd2016+2.56+4.61
Coolest139th1902-1.23-2.21

Precipitation

September Precipitation

The maps shown above 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 September 2019 varied significantly around the world. September precipitation was generally drier than normal across much of the south-central and eastern contiguous U.S., northeastern Brazil, southern South America, southeastern Europe, Australia, and across parts of eastern Asia. Wetter-than-normal conditions were notable across the northern contiguous U.S., northern Europe, India, South Korea, and parts of central Russia.

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):

  • Much of Australia had below-average precipitation during September 2019. Overall, Australia had its tenth driest September in the nation's 120-year precipitation record at 59% below average. Queensland had the highest precipitation deficit at 86% below average and had its 11th (tied) driest September on record. Western Australia had its fifth driest September on record at 68% below average.
  • Drier-than-average conditions plagued much of Argentina during September 2019. Overall this was the nation's second driest September since national records began in 1961.

Ocean Heat Content

Ocean Heat Content (OHC) is essential for understanding and modeling global climate since > 90% of excess heat in the Earth's system is absorbed by the ocean. Further, expansion due to increased ocean heat contributes to sea level rise. Change in OHC is calculated from the difference of observed temperature profiles from the long-term mean.

July–September 2019 Ocean Heat Content (1022 joules)
Basin0-700 meters | Rank (1955-2023)
Entire BasinNorthern HemisphereSouthern Hemisphere
Atlantic7.5134th4.3025th3.2112nd
Indian3.6604th0.9833rd2.6778th
Pacific6.0466th3.1175th2.9297th
World17.2194th8.4024th8.8176th
Source: Basin time series of heat content
July–September 2019 Heat Content 0-700 m
Heat Content 0-700 m

Global OHC for July–September 2019 was the highest July–September OHC in our records, which extend back to 1955. Overall, the latest quarterly OHC reveals widespread warmer than normal, i.e. the 1955–2006 mean, conditions, a situation observed since the end of 2016. Cool conditions, about -10x105 J/m3, appear in the eastern equatorial Pacific Ocean, breaking warmer than normal conditions observed in the area since April–June 2018. Much warmer, > 30x105 J/m3, than normal conditions have developed in high latitudes off the tip of the Antarctic Peninsula and the norteastern coast of Greenland. Much cooler, < -30x10^5 J/m^3, conditions continue to exist around the Phillipines in the tropical and subtropical western Pacific Ocean, with the cool signal extending northeastward into the central North Pacific Ocean. As in the previous quarter, much higher, > 30x105 J/m3, than normal OHC conditions are observed in the Gulf Stream/North Atlantic Current, the Kuroshio Current/Kuroshio Extension, the Brazil Current, the Southwestern Atlantic Ocean, and along the northern Antarctic Circumpolar Current in the Indian Ocean. Cooler than normal conditions persist in the subpolar North Atlantic Ocean south of Greenland and Iceland, and along the central Antarctic Circumpolar Current in the Indian and Pacific Oceans sectors.

References


Citing This Report

NOAA National Centers for Environmental Information, Monthly Global Climate Report for September 2019, published online October 2019, retrieved on March 28, 2024 from https://www.ncei.noaa.gov/access/monitoring/monthly-report/global/201909.