On 23 November 2025, the Hayli Gubbi volcano in Ethiopia produced a large eruption whose ash plume rose tens of kilometres into the atmosphere. Winds carried fine ash eastward across the Red Sea, the Arabian Peninsula and into South Asia. Satellite tracking and meteorological agencies reported the ash mass moved across Gujarat and parts of north-west India before shifting toward China; India’s Meteorological Department (IMD) said the plume cleared Indian skies within a short window.

The ash cloud prompted immediate operational responses from airlines. Indian carriers, including Air India and Akasa Air, cancelled and rerouted some flights as a precaution; regulators and the Volcanic Ash Advisory Centers issued advisories warning aircraft to avoid ash-contaminated airspace because volcanic glass particles can damage jet engines and instruments.

Did the ash cause Delhi’s poor air quality?

Delhi’s Air Quality Index (AQI) was already in a “very poor” to “severe” category because of wintertime emissions (traffic, biomass burning, local meteorology). Some media and agencies noted that the ash plume passed over the region while the AQI remained poor; other official updates said the ash was unlikely to be the main driver of the pollution episode and that most ash had moved out of Indian airspace within hours.

Flight safety: why volcanic ash is treated seriously

Volcanic ash contains abrasive glass and mineral particles that can:

• abrade cockpit windshields and sensors;

• clog or melt in turbine engines, causing power loss;

• reduce visibility and impair navigation instruments.

Because of these risks, aviation authorities worldwide use advisory systems (VAACs) and operational guidance to reroute or ground flights when concentrated ash is forecast along flight paths. During the Hayli Gubbi event, several international and regional flights were cancelled or delayed while carriers performed safety checks and flight-planning adjustments.

Health hazards of breathing volcanic ash and “volcanic smog”

Volcanic ash is composed of very small, often respirable particles. Health effects depend on exposure concentration, duration and individual susceptibility. Documented acute effects include: eye and skin irritation, sore throat, coughing and shortness of breath. People with pre-existing respiratory disease (asthma, COPD), cardiovascular disease, children and older adults are at higher risk of significant symptoms. Long-term effects are less clearly defined but repeated, high-level exposure can exacerbate chronic lung disease. Public-health agencies recommend limiting outdoor exposure, using well-fitting masks (N95/FFP2 where available) if outdoors, and seeking medical care for worsening symptoms.

Practical advice for the public

• Check local AQI and official advisories before going outdoors. If AQI is high or ash advisories are active, reduce outdoor activity.

• People with asthma/COPD should have inhalers/medications ready and follow their clinician’s action plan. Seek immediate care for severe breathlessness.

• If ash is visible, avoid unnecessary driving (ash reduces visibility and can make roads slippery). Keep windows and doors closed; seal gaps where ash may enter.

• Use N95/FFP2 masks if you must go outside while ash is present, surgical masks do not reliably filter fine ash or PM2.5.

• Rinse eyes with clean water for irritation and avoid rubbing; consult a clinician for persistent eye pain or vision changes.

What authorities did and what to watch next

Civil aviation authorities and airlines issued route and operational notices; the IMD and VAAC bulletins tracked ash dispersal and forecasted when Indian airspace would clear. Meteorological agencies reported the plume moved out of most of India within a day, but localised effects can vary with wind and mixing height. Environmental and health agencies will monitor AQI trends and hospital presentations to assess any short-term health impacts.

(Rh/TL)