Report on Global High Temperature Trend Analysis 2025: Challenges in Response to Widespread, Intense, and Prolonged Heat
I. Global Climate Background and Long-Term Trends
Normalization of Record-Breaking High Temperatures
The global average temperature in 2024 exceeded the pre-industrial level by 1.5°C for the first time, and this trend continued in 2025. As of July, 102 meteorological stations had set new records for daily maximum temperatures, with many areas in China, Europe, North America, and Africa experiencing extreme heat above 40°C.
WMO Prediction: There is an 80% probability that the period 2025–2029 will see a “warmest year,” with an 86% probability that at least one year will exceed 1.5°C, and a 70% possibility that the five-year average will break the 1.5°C threshold. Each 0.1°C increase will significantly 加剧 the risk of disasters such as droughts and floods.
The Game Between El Niño and La Niña
Current sea surface temperatures in the Pacific are in a neutral state (ENSO-neutral), and it is expected to remain so during the Northern Hemisphere summer (June–August); the probability of La Niña will rise to 41% in autumn (September–November), but the neutral state will still account for 48%; the probability of La Niña will increase in winter (December–February) but remain close to neutral.
Impact Differences: La Niña may strengthen the East Asian summer monsoon to alleviate high temperatures in eastern China, but it will prolong droughts in the southwestern United States; under the neutral state, global heat distribution will be more balanced, and local heatwaves will last longer.
II. Regional Predictions on the Duration of High Temperatures
Major Regions in the Northern Hemisphere
China: High temperatures in the Yangtze River Basin and Huanghuai region will peak in mid-August, gradually ease in late August as the subtropical high retreats eastward, but there will still be periodic high temperatures before mid-September; southern China will experience intermittent cooling in late August due to typhoons, and “autumn tigers” (late-summer heatwaves) need to be guarded against in early September.
Indian Subcontinent: Monsoon rains may weaken in September, and high temperatures in the northern plains may persist until October, with some areas exceeding 38°C in the afternoon.
Middle East: Summer high temperatures along the Persian Gulf coast (such as Dubai and Kuwait City) will continue until September, with daytime temperatures generally exceeding 45°C and limited nighttime cooling.
Southern Europe: The Iberian Peninsula, Italy, and other places will still experience heatwaves above 40°C in August, which will ease in late August as the westerlies shift southward, but may rebound briefly in early September.
Northern Europe: Affected by abnormal Arctic vortices, there will be more days of summer high temperatures. The average temperature in August in Stockholm, Oslo, and other places may be 2–3°C higher than normal, returning to normal in early September.
Southwestern United States: The “heat dome” phenomenon may persist until early August, with the apparent temperature reaching 46°C in Phoenix and Las Vegas, easing after mid-August with monsoon rains.
Western Canada: The risk of wildfires will continue until September, and the combination of high temperatures and smoke in places like Vancouver Island threatens health.
Sub-Saharan Africa: From May 2024 to May 2025, 42 countries experienced extreme heatwaves, with Nigeria, Sudan, and other places having temperatures exceeding the 90th historical percentile for several consecutive months. It is expected to heat up again after September as the rainy season ends.
North Africa: Summer high temperatures in Algeria, Libya, and other places will continue until September, and the minimum nighttime temperature on the edge of the Sahara Desert may exceed 30°C.
Major Regions in the Southern Hemisphere
Australia: Unusually warm during winter (June–August), with nighttime minimum temperatures in Sydney, Melbourne, and other places 2–3°C higher than normal; high temperature warnings may be issued in the south; after September, spring will arrive, and a new wave of heatwaves may occur on the eastern coast.
Brazil: Temperatures were higher than normal but not extreme in autumn (March–June), with possible cold air activity in the south; high temperatures are expected to reappear in summer (December–February), with places like Rio de Janeiro possibly exceeding 40°C.
Argentina: The temperature in the capital Buenos Aires nearly reached 50°C in the summer of 2024, and similar extreme high temperatures may recur in the summer of 2025 (December–February), requiring attention to model updates.
III. Key Time Nodes and Risk Warnings
Late August
The scope of high temperatures in the Northern Hemisphere will reach its peak, with many places in China, Europe, and North America experiencing extreme heat above 40°C. The surge in electricity demand may trigger an energy crisis; the Southern Hemisphere will be unusually warm in winter, and southern Australia needs to guard against ecological risks from the combination of high temperatures and drought.
September–October
Northern Hemisphere: High temperatures in North China and Huanghuai regions will ease, but “autumn tigers” may appear in the Yangtze River Basin; drought in the southwestern United States will continue, and the risk of wildfires in California will escalate.
Southern Hemisphere: Brazil and Argentina will enter spring, with high temperatures gradually emerging, requiring vigilance against the impact of drought in agricultural areas on food production.
After November
Northern Hemisphere: East Asia and Europe will enter winter, with alternating cold waves and extreme low temperatures, but mid-latitude regions may experience unusually warm winters.
Southern Hemisphere: Summer high temperatures will start in Australia and South America, and if La Niña forms, it may exacerbate rainfall in Southeast Asia and drought in South America.
IV. Response Strategies and Long-Term Challenges
Short-Term Defense Measures
Infrastructure: Upgrade power grids, optimize measures to alleviate urban heat islands (such as green roofs and permeable pavements), and ensure energy supply.
Health Protection: Establish high-temperature early warning systems, and provide cooling places and medical support for vulnerable groups.
Agricultural Adaptation: Promote drought-resistant crop varieties and strengthen irrigation management to cope with the threat of drought to food security.
Long-Term Strategies
Emission Reduction and Energy Transition: Accelerate the phase-out of fossil fuels, expand the proportion of renewable energy, and strive to control temperature rise within 1.5°C.
Ecological Protection: Restore carbon sinks such as wetlands and forests, and enhance ecosystem resilience.
High temperatures in 2025 will be characterized by “a significant peak in the Northern Hemisphere summer, unusually warm winters in the Southern Hemisphere, and frequent global extreme events.” Although the subsidence time varies across regions, the global warming trend is irreversible. WMO warns that without urgent action, temperatures will continue to break records in the next five years, and climate risks will further escalate. Individuals and society need to adapt to short-term challenges while promoting systemic changes to cope with this “endless climate crisis.”
