April 2020 Global Climate Report

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 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 April 2020 map—is generally reflected by areas of positive and negative temperature anomalies at the surface, respectively.

Monthly Temperature: April 2020

During April 2020, warmer-than-average temperatures were present across much of the global land and ocean surfaces. The most notable warm temperature anomalies were present across much of northern Asia, where temperatures were 4.0°C (7.0°F) above average or higher. Other notable warm areas include western Australia, central Europe, the Gulf of Mexico, the Labrador and Bering seas, and across parts of the northern and southern Pacific Ocean and Antarctica, where temperature departures were +2.0°C (+3.6°F). Meanwhile, the most notable cool temperature departures of -2.0°C (-3.6°F) or cooler were present across much of Canada and the eastern contiguous U.S.

April 2020 Blended Land and Sea Surface
Temperature Anomalies in degrees Celsius

April 2020 Blended Land and Sea Surface
Temperature Percentiles

Record-warm April surface temperatures were present across parts of the Atlantic Ocean, Mexico, the Gulf of Mexico, northern South America, Africa, northern Asia, as well as parts of the Indian and western Pacific oceans. Overall, April 2020 had 6.87% of the world's land and ocean surfaces with a record high April temperature since records began in 1951. This was the fourth highest percentage of record warm April temperatures of that era. Only Aprils of 2016 (14.5%), 2010 (9.7%), and 1998 (7.9%) had a higher percentage. No land or ocean areas had record cold April temperatures.

Averaged as a whole, the global land and ocean surface temperature for April 2020 was 1.06°C (1.91°F) above the 20th century average of 13.7°C (56.7°F) and the second highest April temperature in the 141-year record. Only April 2016 was warmer at +1.13°C (+2.03°F). The eight warmest Aprils have occurred since 2010. April 2016 and 2020 were the only Aprils that had a global land and ocean surface temperature departure above 1.0°C (1.8°F). The April 2020 value is also tied with December 2019 as the 11th highest monthly temperature departure in the 1,684-monthly record. April 2020 also marked the 44th consecutive April and the 424th consecutive month with temperatures, at least nominally, above the 20th century average.

The global ocean-only surface temperature during April 2020 was the highest April surface temperature departure on record at 0.83°C (1.49°F) above the 20th century average of 16.0°C (60.9°F). This value surpassed the now second warmest April set in 2016 by 0.02°C (0.04°F). The April 2020 global ocean surface temperature departure also tied with September 2015, February 2016, and July 2019 as the seventh highest monthly global ocean surface temperature departure in the 1,684-monthly record. The eight highest April global ocean surface temperature departures have occurred since 2010.

The global land-only surface temperature departure was 1.66°C (2.99°F) above the 20th century average of 8.1°C (46.5°F)—the second highest on record, behind 2016.

Regionally, the Caribbean region and the Gulf of Mexico had their warmest April since records began at +1.11°C (+2.00°F) and +1.71°C (+3.08°F), respectively. This was the first time the Caribbean region had a temperature departure over 1.0°C (1.8°F) during the month of April. This was also the Caribbean's sixth highest monthly (tied with August 2016) temperature departure in the 1,336-monthly regional record. For the Gulf of Mexico, this was also the largest warm temperature departure for any month on record. Meanwhile, South America, Africa, Asia, and Oceania had an April temperature that ranked among the six highest in the 111-year record.

April Global Land and Ocean Plot

April Global Hemisphere Plot

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:

• Spain had its seventh warmest April since national records began in 1965 with a national temperature of 14.4°C (57.9°F). This is 1.4°C (2.5°F) above the 1981–2010 average. According to Spain's Agencia Estatal de Meteorología, the nation's above-average mean temperature was mainly driven by the nation's much-warmer-than-average minimum temperature (+2.3°C / +4.1°F), which ranked as the third warmest April minimum temperature in the nation's 56-year record. Only Aprils of 2011 and 2014 had a higher minimum temperature departure. April 2020 also marked the 12th consecutive month with national temperatures above average—the longest number of consecutive months with above-average temperatures for the nation.
• The United Kingdom's April 2020 mean temperature was 1.7°C (3.1°F) above the 1981–2010 average and the fifth highest in the nation's records, which date back to 1884. According to the UK Met Office, mean maximum temperatures were 2.5°C (4.5°F) to 4.0°C (7.2°F) above average across England and Wales.
• France had its third warmest April, with a national temperature of 14.1°C (57.4°F) or 3.0°C (5.4°F) above the 1981–2010 average. Only Aprils of 2007 (+3.6°C / +6.5°F) and 2011 (+3.3°C / +5.9°F) were warmer.
• The Kingdom of Bahrain had a national mean temperature of 27.0°C (51.6°F), which is 2.0°C (3.6°F) above the 1981–2020 average. This value tied with April 1999 as the fifth highest mean temperature since national records began in 1902. The nation's minimum temperature was 2.2°C (4.0°F) above average and the third highest for April since 1946. Only Aprils of 2010 and 2017 were warmer.
• Australia's national mean temperature for April 2020 was +1.64°C (2.95°F) above the 1961–1990 average, resulting in the fifth highest April temperature in the nation's 111-year record. Regionally, Western Australia had its second highest April temperature departure at +2.39°C (+4.30°F), which is only 0.22°C (0.40°F) less than the record warm April of 2005. The Northern Territory had its third warmest April, while Queensland had its sixth warmest on record.

Year-to-date Temperature: January–April 2020

The year-to-date global land and ocean surface temperature was also the second highest in the 141-year record at 1.14°C (2.05°F) above the 20th century average of 12.6°C (54.8°F). This was only 0.07°C (0.13°F) less than the record warm January–April set in 2016. According to NCEI's annual temperature outlook, the year 2020 is almost certain to rank among the four warmest years on record. The global land-only and global ocean-only temperature departures for January–April 2020 were also the second highest on record, behind only the record set in 2016.

The first four months of the year had warmer-than-average conditions across much of the globe; however, the most notable warm January–April temperature departures were observed across much of central and eastern Europe and northern Asia, where temperatures were 3.0°C (5.4°F) above average or higher. Meanwhile, the most notable cool temperature departures of -1.5°C (-2.7°F) or cooler were present across Alaska and western parts of Canada. Record-warm January–April temperatures were present across parts of Mexico, Central America, the Gulf of Mexico, South America, the Atlantic Ocean, Europe, Asia, and across parts of the Pacific and southern Indian oceans. However, no land or ocean areas had record cold January–April temperatures.

January–April 2020 Blended Land and Sea Surface
Temperature Anomalies in degrees Celsius

January–April 2020 Blended Land and Sea Surface
Temperature Percentiles

Europe and Asia had their warmest January–April period on record at +2.77°C (+4.99°F) and +3.37°C (+6.07°F), respectively. The Caribbean region and South America had their second warmest year-to-date on record.

January–April Global Land and Ocean Plot

January–April Global Hemisphere Plot

Precipitation

April Precipitation

April 2020 Land-Only Precipitation Anomalies

April 2020 Land-Only Precipitation
Percent of Normal

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 April 2020 varied significantly around the world. April 2020 precipitation was generally drier than normal across much of the western half of the contiguous U.S., northern, central, and eastern Europe, across eastern Asia, and northern New Zealand. Wetter-than-average conditions were present across parts of Alaska, southwestern and much of the eastern contiguous U.S., western Europe, and western 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):

• Wetter-than-average conditions engulfed much of Spain during April 2020. The nation had 40% above-average precipitation, resulting in the 11th wettest April since national records began in 1965. According to Spain's Agencia Estatal de Meteorología, several locations across the Mediterranean coast and some parts of the Balearic Islands had triple their April normal precipitation.
• April 2020 precipitation for Australia was 21% below average. Regionally, Victoria had the highest precipitation, receiving double its monthly normal precipitation and resulting in the third wettest April on record. April 1074 was Victoria's wettest April in the 121-year record. Tasmania had its wettest April since 1960 and the ninth wettest since records began in 1900.

Global Precipitation Climatology Project (GPCP)

The following analysis is based upon the Global Precipitation Climatology Project (GPCP) Interim Climate Data Record. It is provided courtesy of the GPCP Principal Investigator team at the University of Maryland.

The Global Precipitation Climatology Project (GPCP) monthly data set is a long-term (1979-present) analysis (Adler et al., 2018) using a combination of satellite and gauge information. An interim GPCP analysis completed within ~10 days of the end of the month allows its use in climate monitoring.

Fig. 1 GPCP Monthly precipitation analysis, anomaly field and percentage anomaly field for April 2020

Fig. 2 April 1979–2020 GPCP precipitation trend

The gradual northward travel of precipitation features following the sun continues for this time of year. In the tropics broad precipitation maxima are evident at about the Equator in Africa, over the Maritime Continent and South America (Fig. 1-top panel). Peak values in these maxima are over 14 mm day^-1 or 400 mm month^-1. The South Pacific Convergence Zone (SPCZ) stretching southeastward from New Guinea is also very intense. In northern mid-latitudes the maxima originating in eastern parts of China and the U.S. extend northeastward across the oceans. In the Southern Hemisphere the circumpolar maximum at 50–60°S is relatively smooth with weaker peaks than in the Northern Hemisphere. One tropical feature is notable by its absence this April. There is no double ITCZ in the Eastern Pacific, as is usual this time of year. A weak version of the double feature was evident in March, but for April the usual east-west oriented, weaker band south of the main ITCZ is missing (Fig. 1-top panel), but its negative impression can be seen in the anomaly map (Fig. 1-middle panel) from the central to eastern Pacific from 5-10°S at the location where it normally would be.

Large-scale climate conditions, such as ENSO, are approximately neutral, so the tropical precipitation patterns are driven by other, small-scale or regional variations during the month. Across the tropical Pacific tropical cyclones helped provide the anomaly patterns. In the southwest Pacific during the first third of the month, Category Five Tropical Cyclone Harold moved southeastward from east of Papua New Guinea and ravaged the Solomon Islands, Vanuatu, Fiji and Tonga. The swath of strong positive rainfall anomaly follows the storm track. The storm seemingly drew moisture from the surrounding zones producing negative anomalies to each side of the track.

In the Northern Hemisphere the positive rainfall anomaly in the eastern Pacific just north of the Equator was associated with the track of Tropical Depression One-E during the last week of the month. Its definition as a Depression on April 25 marked the earliest formation of a tropical cyclone in the eastern Pacific since reliable records began. Any connection of the first such April cyclone in this region to the aforementioned absence of the double ITCZ is speculation. Some of the positive rain anomalies in the South Indian Ocean are also related to tropical cyclone systems.

This time of year is the rainy season across Equatorial Africa as the seasonal rains shift north with the sun, but this year heavier than normal rains have occurred especially along the east coast in Kenya, Ethiopia and Somalia causing flooding and helping to provide a good environment for breeding locusts which have also plagued the region. Further north the anomaly percentage map (Fig. 1-bottom panel) shows heavier rainfall than climatology in normally dry areas across war-torn Yemen and covering most of Iran; both areas endured floods during the month. Over South America the Amazon had excess rains and the dry zone to the south continued for a third month. Australia was generally dry also, except for the southeast corner and the northern shore which was affected by tropical systems.

Europe was generally dry in April, except for the Iberian peninsula. Over North America the southeast and mid-Atlantic U.S. was wet, while the north central U.S. and most of Canada were drier than normal. A small, wetter than normal feature was centered over southern California, right in the midst of the very large negative precipitation anomaly over most of North America and extending into the Pacific off the U.S. west coast.

Regional precipitation trends over a long period must be related to anomalies during that period. For April the trend map (Fig. 2) and the anomaly map (Fig. 1-middle panel) seem to have a positive correlation with some, but not all, features agreeing in sign. For example, the large-scale features in the tropical Pacific and tropical Atlantic have somewhat similar patterns in the trend and anomaly maps. Other smaller-scale features look similar, e.g., Australia and South America, although Africa does not fit that kind of agreement. Over North America the comparison is mixed, but the southeast and southwest U.S. agree somewhat between the long-term trend and the anomalies for April 2020.

Background discussion of long-term means, variations and trends of global precipitation can be found in Adler et al. (2017).

References

• Menne, M. J., C. N. Williams, B.E. Gleason, J. J Rennie, and J. H. Lawrimore, 2018: The Global Historical Climatology Network Monthly Temperature Dataset, Version 4. J. Climate, in press. https://doi.org/10.1175/JCLI-D-18-0094.1.
• Huang, B., Peter W. Thorne, et. al, 2017: Extended Reconstructed Sea Surface Temperature version 5 (ERSSTv5), Upgrades, validations, and intercomparisons. J. Climate, doi: 10.1175/JCLI-D-16-0836.1
• 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.
• Adler, R., G. Gu, M. Sapiano, J. Wang, G. Huffman 2017. Global Precipitation: Means, Variations and Trends During the Satellite Era (1979-2014). Surveys in Geophysics 38: 679-699, doi:10.1007/s10712-017-9416-4
• Adler, R., M. Sapiano, G. Huffman, J. Wang, G. Gu, D. Bolvin, L. Chiu, U. Schneider, A. Becker, E. Nelkin, P. Xie, R. Ferraro, D. Shin, 2018. The Global Precipitation Climatology Project (GPCP) Monthly Analysis (New Version 2.3) and a Review of 2017 Global Precipitation. Atmosphere. 9(4), 138; doi:10.3390/atmos9040138

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