Late Spring or Early Summer? Heatwaves in April and May in China, Mongolia and Siberia

In April and May 2025, northern Asia experienced unprecedented heatwaves, with record-breaking temperatures recorded in China, Siberia, and Mongolia. These extreme events underscore the intensifying effects of climate change on regional weather patterns.

🔥 China: +47.0°C in Mangxiaohu, Xinjiang

In late April 2025, the town of Mangxiaohu in Xinjiang Province, China, recorded a staggering temperature of +47.0°C, marking the hottest spring day in Chinese history. This extreme heat was part of a broader heatwave that affected northern and central China, with temperatures surpassing 40°C in several areas. The National Meteorological Centre issued heat warnings, and authorities implemented measures to mitigate the impacts on agriculture and public health.

🥵 Siberia: +39.3°C in Uglovskoye, Altai Krai

On May 18, 2025, the town of Uglovskoye in Altai Krai, Russia, located approximately 51.3°N latitude, recorded a temperature of +39.3°C. This set a new May record for Asian Russia and was just 0.4°C below the all-time national May record. Such extreme heat in a region typically known for its cooler climate underscores the intensifying effects of global warming.

🌡️ Mongolia: +39.0°C Recorded

In late May 2025, Mongolia experienced a rare heat surge reaching +39.0°C, among the highest ever recorded for the country in April and May. This temperature was driven by stable high-pressure systems and dry air masses promoting clear skies and intense solar heating. Warm air advection from neighboring regions, including northern China, intensified by shifts in atmospheric circulation patterns, contributed to the extreme temperatures.

16-Day GFS Forecast Outlook (Early June 2025)

Persistent Heat Dome Over Central Asia:
The GFS model indicates a strong, stable high-pressure ridge lingering over much of northern China and Mongolia for the first two weeks of June. This ridge will trap warm, dry air, continuing to push daytime temperatures above seasonal norms, with many places forecast to exceed 35–40°C regularly.
Heatwave Expansion Into Siberia:
Southeastern Siberia, including parts of Altai Krai and the Trans-Baikal region, is expected to experience increasing temperatures, with several days forecast above 30°C and isolated peaks near 35°C. This would prolong the unusual warmth that began in spring.
Dry Conditions and Soil Moisture Deficits:
The GFS forecast shows limited precipitation across these regions, increasing drought stress in southern Siberia, northern Mongolia, and northwest China. This dryness supports the persistence of heatwaves and raises wildfire risks.
Potential Cold Fronts in Northern Siberia:
The forecast suggests cooler air intrusions in far northern Siberia, but these are unlikely to affect the southern heatwave areas significantly.

Summer 2025 Seasonal Forecast

Above-Average Temperatures Expected:
Seasonal climate models and mkweather.com projections anticipate summer 2025 to be warmer than average across northern Asia. China’s northern provinces, Mongolia, and southern Siberia are likely to see persistent heatwaves, with multiple episodes of extreme heat exceeding previous summer maxima.
Enhanced Drought Risk:
The ongoing dryness from spring is projected to continue, especially in Mongolia and western China. Reduced monsoonal moisture inflow may result in below-average rainfall, exacerbating water scarcity and agricultural challenges.
Increased Wildfire Probability:
Siberia’s vast forested regions are at high risk of severe wildfires during summer 2025 due to warm temperatures, dry soils, and accumulated fuel loads from earlier warmth and drought.
Possible Extreme Weather Events:
While heat dominates the forecast, periodic atmospheric instabilities may bring localized heavy rain or storms, especially in eastern China and parts of Mongolia. These could cause flash flooding in some areas already stressed by drought.
Teleconnection Influences:
Key teleconnections such as the Pacific Decadal Oscillation (PDO) and the Arctic Oscillation (AO) are expected to influence the seasonal pattern, possibly intensifying heatwave frequency depending on their phases.

Summary

The short-term GFS forecast signals continuation of the intense heatwave conditions into early June 2025, particularly over northern China and Mongolia, with rising temperatures in southern Siberia. The broader summer 2025 outlook projects above-normal temperatures, heightened drought risk, and wildfire threats across the region.