The hottest summer in human history – a visual timeline
From June to August 2023, a series of extreme weather events exacerbated by climate breakdown caused death and destruction across the globe
As the world sweltered through the hottest three month spell in human history this summer, extreme weather disasters took more than 18,000 lives, drove at least 150,000 people from their homes, affected hundreds of millions of others and caused billions of dollars of damage.
That is a conservative tally from the most widely covered disasters between early June and early September, which have been compiled in the timeline below as a reminder of how tough this period has been and what might lie ahead.
Haiti: 2 June - Misery added to poverty
Unusually intense rains flood towns and villages, killing 42 and destroying more than 10,000 homes.
Canada: 7 June - Fires the size of Greece
Smoke from devastating wildfires in Quebec casts a pall over New York and prompts air quality warnings for tens of millions of people. Over the course of the summer, fires across Canada would go on to burn 17.9m hectares of land, double the previous record. At least six people are killed and thousands evacuated. “The word ‘unprecedented’ doesn’t do justice to the severity of the wildfires in Canada this year,” said Yan Boulanger of Natural Resources Canada. “From a scientific perspective, the doubling of the previous burned area record is shocking.”
Iran: 9 June - Killer gales and severe droughts
Severe wind and rain kill seven people and injured 59 in the northwest regions. Authorities later report 97% of the country is experiencing water shortages amid a persistent drought.
Balkans: 20-23 June - Hailstones the size of cannonballs and flash floods
A supercell brings hailstones,up to 14cm in diameter, to Slovenia and Croatia, destroying crops and tearing the roofs off houses. At least three people die in flash floods in Kosovo and Romania. “A catastrophe of this magnitude has never been recorded here before,” says the council head of the worst affected Romanian region, Arad County. Serbia declared an emergency in Belgrade and 50 other municipalities. Thousands of homes are damaged.
Antarctic: 28 June - Texas-sized decline in sea ice
Sea ice in the southern hemisphere drops 1.2m sq km (roughly the size of Texas) below the previous record low for early winter. Monthly records follow for July and August.
South Africa: 29 June - Tornado in the southern winter
Seven people die in heavy rain and wind, followed by a tornado in KwaZulu-Natal. Officials in Durban said: “We are experiencing first hand the true effects of climate change during the winter season.”
India and Pakistan: 5-16 July - The longest-lasting tropical cyclone in the Arabian Sea
Cyclone Biparjoy (which means “calamity”) wreaks havoc for 10 days, killing 12 people in India, injuring 12 and forcing the evacuation of 81,000 people in Pakistan. This came amid a devastating monsoon season. New Delhi endured its wettest July day (9 July) in 40 years with 153mm of rain. A landslide in Raigad kills at least 16 with more than 100 feared missing under debris.
China: 7 July - Air raid shelters converted into heat refuges
Beijing suspends outdoor work after a tour guide in the Summer Palace collapses and dies on the ninth straight day of temperatures over 35C. Hangzhou and Shijiazhuang open air raid shelters as refuges from the heat. Energy companies say they are burning record amounts of coal to meet the demand for air conditioning.
Japan: 10 July - ‘Heaviest rain ever’
Six people die in Kyushu during floods and landslides. Meteorological officials describe the deluge as the “heaviest rain ever”.
Italy: 12 July - Road worker collapses in the street and dies
A 44-year-old road marking painter collapses on the street and dies from heat stress in Lodi, south-east of Milan, as temperatures soar above 40C in Europe’s Cerberus heatwave.
Pakistan: 9 July - Grief at monsoon death toll
Monsoon rains lash Lahore and other regions, taking the toll since June to 76 deaths and 133 injuries.
Israel: 15 July - Prime minister taken to hospital with dehydration
The Israeli prime minister, Benjamin Netanyahu, is rushed to hospital with suspected dehydration following a day spent in the sun without a hat or water.
China: 16 July - All-time heat record shattered
An all-time China temperature record of 52.2C is set in Sanbao, exceeding the previous high by almost two degrees.
US: 17 July - Death Valley sets world midnight temperature record
Death Valley records the highest midnight temperature in world history of 48.9C as heat tourists flock to the area.
Mexico: 16 July - Surge in heat deaths
The government reports 167 deaths from extreme heat since March, dozens more than the previous year. This comes amid a record-long and wide heatwave that sees temperatures rise to 42C in the Valles Centrales and other areas.
US: 16 July - Broken air conditioner proves fatal in record heatwave
A Texan man dies after suffering heat stroke when the air conditioner breaks down in his Harris County home amid extreme temperatures in the southern US. The protracted heatwave stretching from Florida to California breaks 2,300 temperature records, takes dozens of lives and affects close to 100 million people.
Algeria: 16 July - Fainting in the road
A 55-year-old man in Relizane dies amid a record heatwave, with temperatures over 50C paralysing outside activity after 10am. About 50 people are taken to hospital after fainting on the street, according to local media.
USA: 17 July - Fatal flash floods
After days of heavy rain, flash floods sweep across swathes of the US’s north-east, killing at least seven people in Pennsylvania and one in New York, flooding roads, cutting electricity supplies and forcing the cancellation of nearly 1,500 flights.
Spain: 17 July - Crisis declared in the olive oil industry
A heatwave and record temperatures in parts of the country (Catalonia records its hottest day with temperatures of 45.3C) scorch crops, leading annual production forecasts to be more than a third below average for the second consecutive year. Extreme weather also threatens rice production in Asia and soy production in the US and South America.
Italy: 18 July - Hospitals adopt Covid-style protocols
Medical institutions enter emergency mode to cope with a rise in emergency cases related to heat-stress as temperatures across the country soared to historic highs. Rome bakes in 41.8C, smashing the city’s previous record set last year by more than a degree. In Sardinia, the mercury rose to 45C.
Greece: 23 July - Biggest wildfire evacuation in history
More than 20,000 people are relocated from Rhodes as swathes of the island are engulfed by fire. Greece suffers the longest and most intense heatwave in the country’s history. A national record of 46.4C is set at Gytheio, and Athens is so hot that authorities close the Acropolis at midday.
Italy: 24 July - Hailstones damage jetliner wings
A Delta Air Lines flight is forced to make an emergency landing in Rome after its wings are damaged by giant hailstones during a supercell storm in northern Italy. In Lombardy, two people are killed by falling trees.
South Korea: 25 June to 26 July - Dozens killed in torrential rains
Forty-seven people are killed in the country’s third most intense monsoon season on record.
China: 26-30 July - Beijing’s most intense downpour in history
Floods in the capital kill 44 people. Dozens more die across northern China as some areas received a year’s worth of rain in one week. The economic damage is estimated at more than $2bn. Two weeks after this, a mudslide in Xi’an buries 21 people and forces the evacuation of 17,000 after the consecutive typhoons Khanun and Doksuri.
Russia: July 30 - Storm causes campsite carnage
Eight campers are killed and 27 are injured in a fierce storm in Mari El on the bank of the Volga River that brings trees down onto the tents.
UK: 4 August - Europe Heatwave costs world 0.6% of GDP
A study by the Allianz insurance company estimates the heatwaves of the previous three months cost the world 0.6% of GDP in lost working hours, even without calculating the greater effects on health, infrastructure and agricultural production. Separately, other insurance companies appear to be reducing their exposure to climate risks by raising premiums and denying cover in areas at high risk of wildfires and storms.
Chile: 5 August - Off-the-charts winter heat record in Andean mountains
Freakish winter heat above 37C in the Andean mountains of South America prompts meteorologist to declare: “This event is rewriting all climatic books.”
Slovenia and Georgia: 6 August - Deaths after record rain
A month’s worth of rain in just 24 hours soaks Slovenia, killing three and causing an estimated €500m of damage. Nineteen die in a mudslide in the Shovi region of Georgia.
Hawaii: 8 August - Deadliest wildfire in US history
An uncontrolled blaze kills at least 97 in Lahaina on Maui island. A drier than usual summer had created tinderbox conditions in an area where fire-resistant native vegetation had long ago been replaced by sugarcane plantations and invasive grasses.
Nepal: 8 August - High mountains no refuge from deadly rains
The government announces that landslides and floods during this year’s monsoon have killed 38 people, destroyed countless homes and blocked a major highway.
Greece: 22 August - 18 migrants killed in EU’s biggest fire
The corpses, including those of two children, found in Dadia national forest are among 21 victims of the biggest wildfire in the EU since records began. Even the local hospital at the regional capital of Alexandroupoli has to be evacuated. Dozens of other fires erupted throughout the summer. A month earlier, 20,000 people, including holidaymakers, were rescued from fires on the island of Rhodes in what was described as the biggest evacuation in modern Greek history.
US: 23 August - Morgues run out of space for bodies during record heatwave
Morgues in Maricopa County, Arizona order extra coolers after a record 44 heat related deaths in one week. The previous month, Phoenix endured daily highs over 43.3C (110F) for 31 days in a row (smashing the record of 17 days from 1974).
US: 22 August - Hilary smashes state rainfall records
Nevada’s daily rainfall record is doubled during Tropical Storm Hilary, which also set records in Idaho, Montana and Oregon. It had previously swept through Mexico, killing one man, and deluged California.
Tajikistan: 28-30 August - Central Asia’s deadly downpour
Three days of torrential rain near the capital caused floods, landslides and mudflows that kill at least 21 people in the central region near Dushanbe.
US: 30 August - Heatstroke blamed for record number of migrant deaths
The number of migrant deaths in El Paso hits a record annual high of 136, largely due to extreme heat, according to a US Border Patrol report. This is almost double the figure for the entirety of last year. “Migrants have told us they are being held without sufficient food or water on the Mexican side, or they were waiting for hours in the desert for the opportunity to cross,” said one official.
Brazil: 5 September - ‘Worst ever’ climate catastrophe in southern state
The governor of Rio Grande do Sul says his state has suffered its worst ever death toll due to a climate event after an extratropical cyclone kills 31 and leaves over 1,600 homeless.
Hong Kong
8 September
Heaviest rain since records began
The most intense downpour in 140 years kills two and injures more than 100 as Typhoon Haikui sweeps across southern China.
Libya
9-11 September
World’s deadliest weather event of the year.
More than 11,300 people are killed in flooding in the coastal city of Derna after record rainfall leads to the collapse of dams. In a single day, Storm Daniel unleashed 200 times as much rain as usually falls on the city in the entire month of September. Human-induced climate change made this up to 50 times more likely.
Heatwaves, fires, floods and storms occur every year, but their intensity is being steadily amplified by human-caused climate disruption, and in 2023, given an extra boost by an El Niño. Scientists have examined a selection of these events and found human emissions massively loaded the dice in favour of disaster.
The final death toll from these months is likely to be far higher than the casualty figures reported at the time because excess heat deaths take many months to calculate.
It is also a taste of more to come. This summer’s heatwave – or worse – is forecast to occur two out of every five years if global heating reaches 2C above pre-industrial levels, and the world is currently on course to go much higher in the coming decades.
