Global Seasonal Climate Update for August-September-October 2026
- A strong El Niño is developing and expected to strengthen during August–October 2026
- Above-normal temperatures are expected worldwide.
- Rainfall patterns show a classic El Niño footprint: Wetter conditions are expected in some regions, while drought risk increases in others
- A positive Indian Ocean Dipole is expected to develop
- Forecasts provide a window for early action and support decision making
- WMO community mobilizes to save lives and livelihoods
Outlook for Oceanic Drivers for the Next Season: For the August–October 2026 (ASO 2026) season, the multi-model ensemble (MME) indicates a rapid development toward strong El Niño conditions. The seasonal average SST anomaly is forecast to reach approximately 2.9°C during ASO 2026, with the intensification trajectory peaking in November. The spread among individual forecast systems remains narrow, reflecting high forecast confidence.
In the Indian Ocean, a positive IOD phase is also expected to develop, reaching an ASO 2026 seasonal mean value of 0.6°C. Meanwhile, the equatorial Atlantic basin is forecast to remain generally warm, with SSTs in both the North and South Tropical Atlantic remaining above normal.
About the Global Seasonal Climate Updates series
The Global Seasonal Climate Update (GSCU) is WMO's flagship seasonal climate outlook, providing authoritative information on the current state of the climate system and expected temperature and rainfall patterns for the coming three months. Issued monthly, the GSCU brings together the latest global climate science to support informed decision-making worldwide.
