August 2023 Monthly Global Climate Report

August 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 These factors, together, mean that calculations from the past may be superseded by the most recent data and can affect the numbers reported in the monthly climate reports.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.

Note: At the time of this report's publication, we are aware of a potential issue with data from two buoys in the Northern Hemisphere. We are working to address the issue, but in the meantime we do not believe global temperatures in the report are affected in any significant way.

August 2023

The August global surface temperature was 1.25°C (2.25°F) above the 20th-century average of 15.6°C (60.1°F), making it the warmest August on record. This marked the first time an August temperature exceeded 1.0°C (1.8°F) above the long-term average. August 2023 was 0.29°C (0.52°F) warmer than the previous August record from 2016, but the anomaly was 0.10°C (0.18°F) lower than the all-time highest monthly temperature anomaly on record (March 2016). However, the August 2023 temperature anomaly was the third-highest anomaly of any month on record. August 2023 marked the 45th-consecutive August and the 534th-consecutive month with temperatures at least nominally above the 20th-century average.

For the fifth consecutive month, global ocean surface temperature hit a record high. El Niño conditions that emerged in June continued into August, and NOAA's Climate Prediction Center issued a statement announcing a greater than 95% chance that El Niño will continue through the Northern Hemisphere winter. Globally, August 2023 set a record for the highest monthly sea surface temperature anomaly (+1.03°C or +1.85°F) of any month in NOAA's 174-year record.

Temperatures were above average throughout most of South America, Africa, Asia, North America, the Arctic and Oceania. Parts of southern North America, central South America, western and central Africa, central, southern, and eastern Asia, and northwestern and eastern Oceania experienced record-warm temperatures this month. Sea surface temperatures were above average across much of the northern, western, and southeastern Pacific, the Atlantic and the Indian Oceans. Record-warm temperatures covered nearly 13% of the world's surface this August, which was the highest August percentage since the start of records in 1951.

Temperatures were near to cooler than average across parts of the western and northeastern U.S., northeastern Russia and Antarctica. Sea surface temperatures were near to below average over parts of the southeastern and eastern tropical Pacific. Less than 1% of the world's surface had a record-cold August.

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

North America, Asia, Africa, and South America each had their warmest August on record. South America had its highest monthly temperature anomaly of any month on record at +2.40°C (+4.32°F).

Peru had its warmest August on record.
- August in Japan ranked warmest on record.
Hong Kong recorded its warmest August on record.
Turkey recorded its second-warmest August on record.
- August in Israel ranked fifth warmest since records began in 1950.
- The Arctic had its warmest August on record.
- The Caribbean region had its warmest August on record.
- It was a record-warm August for the Gulf of Mexico.
- August in the contiguous U.S. ranked ninth warmest on record.

Europe and Oceania each had their second-warmest August.

Spain tied 2003 for its warmest August on record, and the Spanish Peninsula and Balearic Islands sweltered under a heatwave for 16 days in August.
- August in Portugal ranked fifth warmest on record.
Italy recorded its 14th-warmest August on record.
- August in Switzerland ranked among the ten warmest on record.
- August in Estonia was 1.3°C warmer than the long-term average.
Latvia had its 8th-warmest August on record.
- Averaged as a country, Australia had its second-warmest August since records began in 1910.
- Meanwhile, New Zealand had its coolest August in seven years.

| August | 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.

June–August 2023

The June–August 2023 global surface temperature was 1.15°C (2.07°F) above the 20th-century average. This ranks as the warmest June–August period in the 174-year record. The past ten June–August periods have been the warmest such periods on record.

The June–August period is defined as the Northern Hemisphere's meteorological summer and the Southern Hemisphere's meteorological winter. The Northern Hemisphere summer 2023 temperature ranked warmest on record at 1.44°C (2.59°F) above average. June–August 2023 marked the 45th consecutive warmer-than-average summer in the Northern Hemisphere. The Southern Hemisphere winter 2023 temperature was also the warmest on record at 0.85°C (1.53°F) above average, and marked the 55th consecutive warmer-than-average winter in the Southern Hemisphere.

Asia, Africa, North America, South America and Oceania had their warmest June–August periods on record.

Japan had its warmest summer since records began in 1898.
Hong Kong had its warmest summer on record.
- Winter in Australia ranked warmest on record.
New Zealand recorded its fifth-warmest winter since records began in 1909.
The contiguous U.S. had its 15th-warmest summer on record.
- The Caribbean Islands had their warmest summer on record.

Europe had its third-warmest summer on record.

France had its fourth-warmest summer on record.
- Summer 2023 in Italy ranked eighth warmest on record.
Switzerland had its fifth-warmest summer on record.
The United Kingdom reported provisionally its eight-warmest summer since records began in 1884.
Germany reported its 27th consecutive warmer-than-average summer.

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

Over the land surface, temperatures for the season were above average throughout much of North America, South America, Europe, Africa, Asia, Oceania, and the Arctic. Parts of eastern Oceania, central, southern, and eastern Asia, western and central Africa, South America, and southern and northern North America experienced record-warm temperatures this June–August season. Temperatures were near or below average across parts of the central and eastern U.S., western Russia, Antarctica, and India and Pakistan.

Sea surface temperatures for the season were above average across much of the northern, western, and central-eastern Pacific (off the coast of northern South America), and the Atlantic and Indian Oceans. Sea surface temperatures were near or below average across parts of the equatorial eastern and southeastern Pacific Ocean.

| June–August | 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–August 2023

The January–August global surface temperature ranked second warmest in the 174-year record at 1.06°C (1.91°F) above the 1901–2000 average of 14.0°C (57.3°F). January–August 2016—another year with El Niño conditions—holds the record for the warmest such period on record by just 0.03°C (0.05°F) above the current year-to-date anomaly. Global ocean surface temperature during this January–August 2023 period ranked warmest on record. According to NCEI's statistical analysis, there is a 95% probability of 2023 ranking among the two warmest years on record.

January to August was characterized by warmer-than-average conditions across much of eastern, southern, and northern North America, South America, Europe, Africa, the Arctic, northern and southern Oceania, and Asia. Sea surface temperatures were above-average throughout most of the northern, western, southwestern, and subtropical eastern Pacific, central and southern Atlantic, and Indian Oceans. The Southern Hemisphere had its warmest year-to-date period, while the Northern Hemisphere had its third-warmest such period.

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

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

| January–August | 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.

August 2023

Above-average August precipitation was observed across parts of the western and northeastern United States, northern Europe, western Russia and scattered areas in eastern Asia. Meanwhile, drier-than-average conditions were present across much of the southwestern United States, southwestern Europe, India and Pakistan, central South America, Brazil 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.

August and Seasonal Highlights:

- The ongoing El Niño helped intensify the eastern Pacific Intertropical Convergence Zone (ITCZ) and provided dry conditions over most of the Maritime Continent.
- The South Asian monsoon was dry over India and wet over China.
- The west coast of the U.S. was wetter than normal with Hurricane Hilary drenching southern California, while the rest of the U.S. Southwest was dry, along with Mexico and Central America.
- The June–August season reflected El Niño in the tropical Pacific region and had a very high global precipitation total.

The global precipitation map for August 2023 (Fig. 1, top panel) shows a very active tropical region with an intense ITCZ across the eastern Pacific just above the equator, and a broad area of heavy rain in the Western Pacific with multiple imbedded monthly rainfall peaks, most associated with tropical cyclones. The usual South Asian monsoon rainfall maximum covers the Indian sub-continent and eastward through Indochina and South China.

These and other seasonal climatological features across the globe remain relatively constant year-to-year, but are modified from their climatological mean in subtle ways related to the presence or absence of storms, inter-annual influences such as El Niño/La Niña, and even climate change. The middle and bottom panels of Fig. 1 display the anomalies and percentage anomalies for the month (from the climatological means) for August 2023. The ITCZ in the eastern Pacific was strikingly intense with strong, positive anomalies from the central ocean to the South American coast. A narrow band of negative anomalies lie just to the north of the narrow band of positives, indicating a slight shift southward of the climatological ITCZ position. In the western Pacific, the anomaly patterns showed a pattern mostly related to wanderings of tropical cyclones which stayed offshore for the most part, although Typhoon Lan hit southern Japan with heavy rain and flooding.

To the west, much of southeast Asia and the Maritime Continent (New Guinea, Borneo, etc.) had an August rain deficit. That dry feature extends westward over most of the Indian sub-continent, although a rain surplus exists over Bangladesh and over most of China. Heavy rains in northern Vietnam caused landslides there. The general pattern of dryness over the Maritime Continent and above-average rainfall over the central/eastern tropical Pacific is related to the ongoing El Niño, whose Niño 3.4 ST anomaly index increased again this month up to +1.3. Fig. 2 shows the August composite for El Niño conditions, along with a repeat of the anomaly pattern for this August. Over the areas already mentioned, there is a general agreement between the two plots and this August's dryness in Australia and in northern South America also match. However, just to the north of the ITCZ in the Pacific a large area of dryness exists in Fig. 2 for this August, while the composite shows a wide area of positive anomalies typical of past El Niño conditions. The devastating wildfires in Hawaii in early August were associated with the ongoing drought there, which is not typical of El Niño conditions.

Over Africa, the anomaly map shows a pattern of the normal broad rainfall feature with a northern half rainier than normal and the southern half drier than normal, indicating a northerly shift. South America is dry in the north as already mentioned, with a varying pattern to the south, somewhat aligned with the El Niño composite. In Europe, above-average rainfall helped alleviate a general drought, except over Iberia, although floods did occur in eastern Europe (Slovenia, Georgia).

The usually relatively dry west coast of the U.S. had above average rainfall, including an unusual landfall of eastern Pacific Hurricane Hilary taking a northerly course and hitting southern California and Nevada with 10" of rain and associated flooding, even in the desert. Further to the east, across the rest of the southwest, heat and drought conditions prevailed. Wildfires were seen in Louisiana. These very dry conditions extended to the south through most of Mexico and Central America, causing low water conditions in the Panama Canal that affected ship traffic. Further to the east, tropical cyclones had rainfall impacts. Tropical Storm Franklin moved across the island of Dominica and continued north, leaving a rainfall trail east of the U.S. And at the end of the month, Hurricane Idalia developed in the Caribbean, intensified in the Gulf, and hit the Big Bend area of Florida and caused flooding from rain in Georgia and South Carolina.

The mean precipitation for the June–August 2023 season (and the associated anomaly pattern) is shown in Fig. 3. The last three months have had the highest mean global surface temperature since these types of estimates have been made, a result related to global warming combined with the ongoing El Niño. The mean map for the season (top panel) displays the usual climatological features, while the anomaly map (bottom panel) reflects the gradually intensifying El Niño during these past three months. The most prominent anomaly feature is, again, the narrow positive ITCZ feature running across the entire Pacific from above New Guinea to South America. Northern South America was very dry, as was most of both the North and South Pacific outside the ITCZ, with Hawaii sitting in the middle of the dry zone. The U.S. west coast and northwest were wet, but the southwest U.S. and Central America were dry.

Looking at the seasonal total global precipitation estimates for this past season in comparison with past years (Fig. 4) shows that the global precipitation this past season (2.76 mm/d) is near the record global peak value for this season, mainly related to a high ocean mean value (2.84 mm/d).

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Citing This Report NOAA National Centers for Environmental Information, Monthly Global Climate Report for August 2023, published online September 2023, retrieved on September 15, 2023 from

https://www.ncei.noaa.gov/ access/ monitoring/ monthly-report/ global/ 202308.