Earth had its third-warmest May; record-low May sea ice extent observed in the Antarctic
May and Seasonal Highlights:
- For the second consecutive month, global ocean surface temperatures set a record high.
- North America and South America each had their warmest May on record.
- North America recorded its smallest May snow cover extent on record.
- This March–May period ranked third warmest in the 174-year record.
- Global sea ice extent ranked second smallest on record after May 2019.
- There were three major tropical cyclones in May, tying the long-term record.
Globally, May 2023 was the third-warmest May in the 174-year NOAA record. The year-to-date (January–May) global surface temperature ranked as the fourth warmest such period on record. According to NCEI’s Global Annual Temperature Outlook, it is virtually certain (> 99.0%) that the year 2023 will rank among the 10-warmest years on record and an 89% chance it will rank among the top five.
This monthly summary, developed by scientists at NOAA’s National Centers for Environmental Information, is part of the suite of climate services NOAA provides to government, business, academia and the public to support informed decision-making.
Monthly Global Temperature
The May global surface temperature was 1.75°F (0.97°C) above the 20th-century average of 58.6°F (14.8°C). Last month ranks as the third-warmest May in the 174-year record. May 2023 marked the 47th consecutive May and the 531st consecutive month with temperatures at least nominally above the 20th-century average.
Global ocean temperature hit a record high for May, which marks the second consecutive month where ocean temperatures broke a record. Weak El Niño conditions emerged as above-average sea surface temperatures strengthened across the equatorial Pacific Ocean, prompting NOAA’s Climate Prediction Center to announce the arrival of El Niño conditions which are expected to gradually strengthen into Northern Hemisphere winter 2023–24. Meanwhile, the Northern Hemisphere had its second-warmest May on record. In the Southern Hemisphere, surface temperature ranked fourth warmest on record for the month, but ocean-only temperature hit a record high.
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. Meanwhile, Africa, Asia and Europe each had a top-20 warmest May. Oceania had a cooler-than-average month; it was the region’s coolest May since 2011. Antarctica had a cooler-than-average May, whereas the Arctic had its fifth-warmest May on record.
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.
Sea Ice and Snow Cover
Globally, May 2023 saw the second-lowest sea ice extent on record for the month. Only May 2019 had a smaller global sea ice extent.
Arctic sea ice extent for May 2023 ranked 13th smallest in the satellite record at 4.95 million square miles, or about 40,000 square miles below the 1991–2020 average. The May 2023 Antarctic sea ice extent ranked lowest on record at 3.23 million square miles, or 750,000 square miles below average. This was 190,000 square miles below the previous Antarctic record low from May 2019.
According to data from NOAA and analysis by the Rutgers Global Snow Lab, the Northern Hemisphere snow cover extent during May was 570,000 square miles below the 1991–2020 average. This ranks as the eighth-smallest Northern Hemisphere snow cover extent on record for May. North America recorded its smallest May snow cover extent on record. Extent was near normal across Eurasia.
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. Overall, the global mean precipitation ocean/land difference began to reflect the coming El Niño, along with a very weak positive tropical pattern correlation.
Seasonal Global Temperature
The March–May 2023 global surface temperature was 1.91°F (1.06°C) above the 20th-century average of 56.7°F (13.7°C). This ranks as the third-warmest March–May period in the 174-year record.
The March–May period is defined as the Northern Hemisphere's meteorological spring and the Southern Hemisphere's meteorological fall. The Northern Hemisphere spring temperature was the third warmest on record at 2.32°F (1.29°C) above average. The Southern Hemisphere autumn temperature ranked second warmest on record at 1.49°F (0.83°C) above average.
South America had its second-warmest March–May period on record at 2.39°F (1.33°C) above average. It was the third-warmest March–May period on record for Africa (tied with 2020), while North America, Europe and Asia each had a top-20 warmest such period on record. Oceania had a warmer-than-average autumn, but it was the region’s coolest autumn since 2012.
Global Tropical Cyclones
Three named storms occurred across the globe in May, all of which reached major tropical cyclone strength (≥111 mph). Two storms reached Category 5 on the Saffir-Simpson Hurricane Wind Scale. May 2023 tied 2008 and 2015 for the most major hurricanes in May. The global accumulated cyclone energy was the highest on record in May and about 10% higher than the previous record set in 2015.
In the western Pacific, Super Typhoon Mawar was the second named storm of the year. Typhoon Mawar was the third Category 4 typhoon to pass within 100 miles of Guam in the Western Pacific, and resulted in heavy rainfall and widespread power outages on the island. Cyclone Mocha, which made landfall as a Category 4 cyclone in Myanmar, was the North Indian Ocean’s first named storm of 2023. Winds, rainfall and storm surge associated with Mocha resulted in hundreds of deaths. The only named storm in the Southern Hemisphere during May was Cyclone Fabien, which reached Category 3 strength as it passed near Diego Garcia in the South Indian Ocean. This was only the third year on record with a major cyclone in the Southern Hemisphere during May.
Notice: At the time of this report's publication, some data streams may be incomplete and final numbers are subject to change.