May 2023 Monthly Global Climate Report

May 2023 Global Climate Report | National Centers for Environmental Information (NCEI)

Temperature

Coinciding with the release of the January 2023 Global Climate Report, the NOAA Global Surface Temperature (NOAAGlobalTemp) dataset version 5.1.0 replaced version 5.0.0. This new version includes complete global coverage and an extension of the data record back in time an additional 30 years to January 1850. While anomalies and ranks might differ slightly from what was reported previously, the main conclusions regarding global climate change are very similar to the previous version. Please see our Commonly Asked Questions Document and web story for additional information.

NOAA's National Centers for Environmental Information calculates the global temperature anomaly every month based on preliminary data generated from authoritative datasets of temperature observations from around the globe. The major dataset, NOAAGlobalTemp version 5.1.0, updated in 2023, uses comprehensive data collections of increased global area coverage over both land and ocean surfaces. NOAAGlobalTempv5.1.0 is a reconstructed dataset, meaning that the entire period of record is recalculated each month with new data. Based on those new calculations, the new historical data can bring about updates to previously reported values. These factors, together, mean that calculations from the past may be superseded by the most recent data and can affect the numbers reported in the monthly climate reports. The most current reconstruction analysis is always considered the most representative and precise of the climate system, and it is publicly available through Climate at a Glance.

Notice: At the time of this report's publication, some data streams may be incomplete and final numbers are subject to change.

May 2023

May 2023 was the third-warmest May for the globe in NOAA's 174-year record. The May global surface temperature was 0.97°C (1.75°F) above the 20th-century average of 14.8°C (58.6°F). The past nine Mays have ranked among the 10 warmest on record. May 2023 marked the 47th consecutive May and the 531st consecutive month with global temperatures, at least nominally, above the 20th-century average.

Global ocean surface temperature hit a record high for May, which marks the second-consecutive month where ocean surface temperatures broke a record. On June 8, NOAA's Climate Prediction Center announced an El Niño Advisory alert status; weak El Niño conditions emerged in May as above-average sea surface temperatures strengthened across the equatorial Pacific Ocean. El Niño conditions are now present and are expected to gradually strengthen into the Northern Hemisphere winter 2023–24.

The Northern Hemisphere had its second-warmest May on record, 0.11°C (0.19°F) shy of the record set in May 2020. In the Southern Hemisphere, surface temperature ranked fourth warmest on record for the month. However, ocean-only surface temperature hit a record high in the Southern Hemisphere at 0.81°C (1.46°F) above average. Antarctica had a cooler-than-average May, whereas the Arctic had its fifth-warmest May on record.

Both North America and South America set a record high temperature for May. Amid the unusually high May temperatures in North America, several hundred wildfires broke out across Canadian forests, burning over 6 million acres and causing widespread air quality deterioration across much of Canada and the U.S in late May and early June.

Temperatures were above average throughout most of North America, South America and Africa. Parts of western Europe, northwestern Russia, southeast Asia, the Arctic and northern and southern Oceania also experienced warmer-than-average temperatures this month. Sea surface temperatures were above average across much of the northern and southwestern Pacific, the central and southern Atlantic and the Indian Ocean. Parts of the eastern and southern Atlantic, the southern Pacific, the southwestern Indian Ocean, as well as parts of northwestern Canada and several countries in South America saw record-warm May temperatures. Combined, record-warm temperatures covered just over 6% of the world's surface this month.

Temperatures were near to cooler than average across parts of the southeastern U.S., Greenland, eastern Europe, central and southern Asia, Australia and Antarctica. Sea surface temperatures were near to below average over parts of the central-eastern and southeastern Pacific and the northwestern Atlantic Ocean. Less than 1% of the world's surface had a record-cold May.

A smoothed map of blended land and sea surface temperature anomalies is also available.

North America and South America each had a record-warm May.

- May in the contiguous U.S. ranked 11th warmest on record.
Cuba recorded an average temperature for May that was 0.7°C above the long-term average.
- In Uruguay, average temperatures ranged from 0.9°C to 1.6°C above normal for the month.

Africa had its eighth-warmest May, Asia its 16th-warmest, and Europe its 20th-warmest.

Hong Kong recorded a monthly temperature 0.3°C above the normal (26.3°C), and precipitation was 37% below normal.
- In Pakistan, the national mean temperature for May was 0.71°C below the average. It was Pakistan's second-wettest May on record.
The United Kingdom had its seventh-warmest May.
- Seven stations in Ireland recorded their warmest May, while all stations recorded mean temperatures above their long-term averages.
- May in France was 0.8°C above average.
The Netherlands recorded a near-normal temperature for May.
- Meanwhile, Italy had a cooler-than-average May.

Oceania had a lower-than-average May temperature. It was the region's coolest May since 2011.

New Zealand had its warmest May on record.
- May in Australia was 1.10°C below average, making it the coolest May since 2011. It was Australia's second-driest May on record.

| May | Anomaly | | Rank(out of 174 years) | |
| °C | °F | Year(s) | | |
| Global | | | | |

Ocean Land and Ocean Land Ocean Land and Ocean Land Ocean Land and Ocean

500 mb maps

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

March–May 2023

The March–May 2023 global surface temperature was 1.06°C (1.91°F) above the 20th-century average. This ranks as the third-warmest March–May period in the 174-year record and 0.10°C (0.18°F) cooler than the warmest March–May period (2016). The ten warmest March-May periods have all occurred from 2010 to present.

The March–May period is defined as the Northern Hemisphere's meteorological spring and the Southern Hemisphere's meteorological fall. The Northern Hemisphere spring 2023 temperature ranked third warmest on record, and the Southern Hemisphere autumn temperature was the second warmest on record. Ocean temperature for the season ranked warmest on record for the Southern Hemisphere.

South America had its second-warmest March–May period on record. Africa tied 2020 for its third-warmest March–May period, and Asia had its eighth-warmest such period on record.

North America and Europe each had a top-20 warmest spring on record.

The contiguous U.S. had a spring temperature that was 0.6°F above average, ranking in the middle third of the historical record.
- The Caribbean Islands had their fourth-warmest spring on record.
Spain had its warmest spring since records began in 1961.
- Spring in the United Kingdom was 0.3°C above the 1991–2020 average.
Italy had a spring temperature that was 0.14°C above average, ranking 19th warmest on record.
- Spring in France was 0.6°C above the 1991–2020 normal and ranked 9th warmest on record.
Latvia had its 10th-warmest spring on record.

Although Oceania had a warmer-than-average fall, it was the region's coolest fall since 2012. Both the Antarctic and Arctic had a March–May period that ranked among the 20 warmest (17th and 11th, respectively) on record.

New Zealand had its fourth-warmest autumn on record.
Australia had its coolest autumn since 2012.

Over the land surface, temperatures for the season were above average throughout much of northern, eastern, and southern North America, South America, Europe, Africa, and northern, eastern and southeastern, and western Asia, and the northern and southern reaches of Oceania. Parts of the Arctic, South America, western Europe, western and southeastern Asia, and Micronesia experienced record-warm temperatures this March–May season. Temperatures were near or below average across parts of western North America and Alaska, northern Scandinavia, India and Pakistan, and Antarctica.

Sea surface temperatures for the season were above average across much of the northern, western, and southwestern Pacific, the central and southern Atlantic, and Indian oceans. Sea surface temperatures were near or below average across parts of the equatorial eastern and southeastern Pacific Ocean.

| March–May | Anomaly | Rank(out of 174 years) | Records | |
| | °C | °F | Year(s) | °C |
| Global | | | | |

Ocean Land and Ocean Land Ocean Land and Ocean Land Ocean Land and Ocean

Year-to-date Temperature: January–May 2023

The January–May global surface temperature ranked fourth warmest in the 174-year record at 1.01°C (1.82°F) above the 1901–2000 average of 13.1°C (55.5°F). According to NCEI's statistical analysis, the year 2023 is very likely to rank among the 10 warmest years on record.

January to May was characterized by warmer-than-average conditions across much of eastern, southern, and far northern North America, South America, Europe, Africa, the Arctic, northern and southern Oceania, and Asia with the exception of a small pocket of cooler conditions near India and Pakistan. Sea surface temperatures were above-average throughout most of the northern, western, southwestern, and subtropical eastern Pacific, central and southern Atlantic, and Indian oceans.

Temperatures were near or below average across parts of western North America and western Alaska, India and Pakistan, Greenland, Australia, and Antarctica. Sea surface temperatures were near to below average across parts of the southeastern and equatorial Pacific and northern Atlantic oceans.

A smoothed map of blended land and sea surface temperature anomalies is also available.

Europe and Africa each had their fourth-warmest year-to-date period. South America had its seventh-warmest January–May period, while North America and Asia each had their ninth-warmest such period. Oceania had a warmer-than-average year-to-date period, but it did not rank among the 20 warmest on record. Overall, the Northern Hemisphere had its fourth-warmest year-to-date, while the Southern Hemisphere had its fifth-warmest such period.

| January–May | Anomaly | Rank(out of 174 years) | Records | |
| | °C | °F | Year(s) | °C |
| Global | | | | |

Ocean Land and Ocean Land Ocean Land and Ocean Land Ocean Land and Ocean

Precipitation

The maps shown 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.

May 2023

Above-average May precipitation was observed across parts of the western, central and southern central U.S., southern Europe, northeastern China, South Asia and New Zealand. Meanwhile, drier-than-average conditions were present across much of the northwestern and northeastern U.S., southern South America, northern and eastern Europe, western and central Russia, southeast Asia and Australia.

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.

May and March–May Highlights:

- The global mean precipitation ocean/land difference has begun to reflect the coming El Niño, along with a very weak positive tropical pattern correlation.
- Early season tropical cyclones were seen in the western Pacific, the Bay of Bengal and the South Indian Ocean.
- Canada and Russia were both affected by dry conditions and wildfires.
- The March–May season was accentuated by the transition from La Niña towards El Niño conditions.

For the month of May, and for the March–May season (Northern Hemisphere spring and Southern Hemisphere autumn), transition is the main topic, but for this year an additional transition related to El Niño is layered on top of the seasonal change. The usual climatological features were evident (Fig. 1, top panel), and are easing toward the north, especially over the tropical continents. Remnants of the southern arm of the springtime double Intertropical Convergence Zone (ITCZ) can still be identified, mainly in the far eastern Pacific. The global oceans were very warm, and the ENSO indicator Niño3.4 was +0.4 for the month of May and +0.8 at the end of the month, indicating the ongoing transition toward El Niño conditions.

The precipitation anomaly patterns for May (Fig. 1, middle and bottom panels) show intense anomalies, both positive and negative, across the tropical Pacific Ocean. The positive anomaly along the eastern Pacific ITCZ is El Niño-like and shows a southward shift of the ITCZ (note the negative anomaly just to the north). However, the positive anomaly in the western Pacific stretching from off the Philippines to northeast of Australia is out of place for El Niño. Just to the west, a dry area running from Indochina to Australia fits better with typical El Niño conditions. Overall, in the tropics, 40°N–40°S, the correlation between this month's anomaly field and El Niño composites from previous years was positive, but very small.

The anomaly map also shows results from early season tropical cyclones in the Northern Hemisphere. In the Bay of Bengal, Tropical Cyclone Mocha developed and moved northeastward across the bay and created havoc in Myanmar and far eastern Bangladesh. A part of that western Pacific wet area was related to Typhoon Mawar, the most intense storm in two years, and the most intense in May in 60 years. Mawar came right across Guam, causing significant damage and 20 inches of rain, then tracked to the northwest, avoiding land and recurving and passing to the east of Japan while weakening, but causing flooding in Japan in early June. Even the South Indian Ocean had Tropical Cyclone Fabien, which contributed to the anomaly field while tracking to the west and then south.

In South Asia, Indochina was hot and dry along with southern China, while eastern China had floods. Australia was also very dry, which may be nearly an El Niño effect, while New Zealand was immersed in a positive anomaly feature and again had floods in the Auckland region. Over Africa, the central zone along the equator shows a negative anomaly for the month; however, during the very early days of the month, floods and landslides, with major loss of life, were reported in eastern Congo, Rwanda and Kenya. The negative anomaly there, despite the floods, may be due to a lack of gauge coverage or weakness in the satellite estimates, or merely a very dry rest of the month.

South America had a mottled precipitation anomaly field, with little resemblance to a typical El Niño scenario, although the intense dry area along the northeast coast could be a beginning of a coming drought over the northern part of the continent. Over the Atlantic ITCZ, the shift to the north of the rainfall maximum also looks similar to an El Niño pattern. Further south, Uruguay suffered a dry May, extending their drought, to a point of near empty reservoirs.

Over Europe, dryness and negative rainfall anomalies continued across its northern mid-section, France, Germany and to the east, especially across most of Russia, with wildfires scattered from the Urals to Siberia, with the loss of 20 lives in one event. However, to the south in Europe, there was some relief from a long drought with positive precipitation anomalies for the month running from the Iberian Peninsula, across Italy and into the Balkans. Unfortunately, as often happens, large-scale drought is followed by smaller-scale, intense rainfall and floods. Early in the month, floods hit northeast Italy (Bologna), England and Wales. Later in the month, northeast Italy was hit again and the flooding extended into Bosnia and Croatia.

Central America was very dry in May, related to the position of the offshore ITCZ, but further north from central Mexico into most of the western U.S. surplus precipitation dominated. Outside of that area, below-normal precipitation was seen (except for Alaska) over most of Canada and the eastern half of the continental U.S. This relative lack of rain has produced drought conditions in the northeast U.S., and extensive wildfires in both western and far eastern Canada, and even New Jersey. Smoke from the fires affected the local areas, but was also transported long distances across the continent. The North American anomaly pattern for this May has a similarity to the El Niño composite for May, perhaps indicating an early El Niño effect.

Although the global anomaly pattern for this May is only weakly related to what a stronger El Niño pattern would be, the global ocean/land mean value differentiation has the mean value positive for ocean, negative for land, with an overall global positive anomaly, which are numbers typical of El Niño conditions.

Figure 2 gives the mean precipitation map for the March–May season (top panel) and anomaly map for the period (bottom panel). The mean map (top panel) shows the usual seasonal features, including the double ITCZ in the eastern Pacific. The anomaly map (bottom panel) also contains the results of the La Nina to El Niño ongoing transition and other effects. In the tropics, there is a smaller scale pattern than usual, especially across the Pacific Ocean. This smaller-scale pattern seems to be the result of the mix of larger-scale transitioning ENSO effects. Drought over Indochina, heavy rain over eastern China, and a strong positive anomaly over coastal Ecuador and Peru and coastal waters associated with the very warm waters off the coast associated with the likely start of El Niño in that region. But, the most dominating pattern may be over North America with its positive anomaly in the southwest and negative anomaly everywhere else, related to blooming in the desert southwest of the U.S. and drought conditions and the associated wildfires in Canada, and even the northeast U.S.

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Citing This Report NOAA National Centers for Environmental Information, Monthly Global Climate Report for May 2023, published online June 2023, retrieved on June 14, 2023 from

https://www.ncei.noaa.gov/ access/ monitoring/ monthly-report/ global/ 202305.