El Niño forecast intensifies: heat, drought, heavy-rain risks for health

El Niño conditions are already underway in the tropical Pacific and are forecast to strengthen rapidly, according to two closely timed updates—one from the World Meteorological Organization (WMO) on July 3, 2026 and a related timing/strength assessment from NOAA’s Climate Prediction Center (CPC) on July 9, 2026.

For governments, aid organizations, and public-health planners, the practical implication is not that any single place will be hit in the same way. Instead, the likelihood of multiple climate-linked hazard types—heatwaves, drought and water stress, and heavy rainfall—is rising in many regions, which changes when and how preparedness should ramp up.

What changed in WMO’s latest messaging

WMO says El Niño conditions “have developed” and are expected to “strengthen rapidly over the coming months,” raising the likelihood of heatwaves, droughts, heavy rainfall and other extreme weather events in many parts of the world.

WMO also points to its monthly Global Seasonal Climate Update for July–September 2026 and describes a broad signal for above-normal temperatures over land, including a “nearly universal” enhancement in probabilities. For ocean conditions, the same outlook highlights seasonal-average sea-surface temperature anomalies expected to exceed 2°C in key monitoring regions.

What NOAA adds on persistence and potential strength

NOAA’s CPC ENSO Diagnostic Discussion strengthens the planning timeline. It says El Niño is expected to continue strengthening through the end of the year, with a 97% chance it will persist through early spring 2027.

It also gives a probability signal for higher intensity later in the year: there is an 81% chance of a very strong El Niño during October–December—framed as among the larger events in the historical record.

How these ENSO odds connect to health and humanitarian risk

WHO emphasizes that ENSO-linked shifts can affect health determinants through multiple pathways. These include impacts on food security, air and water quality, ecosystems, and the safety of health infrastructure. WHO also notes ENSO is associated with altered transmission patterns of vector-borne, rodent-borne, and waterborne diseases.

Extreme heat is a particularly direct bridge from climate risk to human harm. WHO’s heat guidance states that heat stress is a leading cause of weather-related deaths and can worsen underlying illnesses. It also warns that heatwaves can reduce health service delivery capacity—especially when power shortages disrupt health facilities, transport, and water infrastructure.

And because ENSO can bring both drought-related stressors and heavy-rain conditions, preparedness has to account for water and sanitation strain from multiple angles: drought can pressure water access, while heavier rainfall can disrupt water systems and affect water quality.

What planners can do now (without pretending forecasts are guarantees)

Because these are probabilistic risks, the most useful next steps focus on capacities that help across scenarios:

• Heat response readiness: ensure heat-health plans, outreach to high-risk groups, and rapid public-health escalation are ready before the hottest periods.
• Water and sanitation continuity thinking: stress-test whether water systems and essential sanitation services can keep operating during heat-related power or infrastructure disruptions—and whether water quality monitoring and distribution contingencies are in place.
• Health system continuity for cascading hazards: plan for disruptions to facility operations, transport, and water infrastructure—not only for immediate heat injuries, but for broader service interruption.
• Early warning and anticipatory action: coordinate early risk surveillance (including climate-sensitive disease monitoring where relevant) so response can begin before localized outbreaks accelerate.

What to watch next: continued WMO seasonal outlook refinement and NOAA CPC updates to the ENSO strength/persistence picture—paired with your local hazard monitoring—because the specific impacts will vary by region even when the global risk signals rise.

Sources

• World Meteorological Organization (WMO) press release: El Niño forecast intensifies—rising likelihood of extreme weather (time-stamped WMO messaging)
• WMO Global Seasonal Climate Update (July–August–September 2026)
• NOAA CPC ENSO Diagnostic Discussion (July 9, 2026)
• World Health Organization (WHO) fact sheet: El Niño Southern Oscillation (ENSO)