What is El Niño?

El Niño is a regularly recurring climate pattern with global implications, historically linked to drought and food insecurity in East Africa and the Horn of Africa, torrential rains or drought in areas of Central America, and other extreme weather events (1).

Scientists are predicting a strong El Niño in 2023, potentially kicking off between the spring and autumn. Whenever it comes, it’s certain to leave global environmental challenges in its wake.

Our warming planet is already experiencing severe, long-lasting heat waves and wildfires. So, is a potentially strong El Niño year likely to lead to even more global brushfires and wildfires?

What are the phases of El Niño?

La Niña and El Niño are recurring climate patterns (2). They're states or phases of the El Niño-Southern Oscillation (ENSO) cycle, a cycle which consists of three phases; La Niña, El Niño, and a neutral phase.

Neutral Phase

What happens in a neutral phase? Normally, warm water in the Pacific Ocean is carried west by trade winds, from South America towards Asia.

La Niña

La Niña, or "the little girl" in Spanish, strengthens the trade winds in the central and eastern Pacific Ocean, pushing warmer air towards Asia. This means that colder water rises to the surface and can have several regional affects for the Americas; warmer winters and more drought in the American South, a greater chance of hurricanes forming, rains and flooding in the Pacific Northwest and Canada.

In Southeast Asia and Australia, La Niña usually heralds wetter conditions (3).

El Niño

Spanish for "the little boy", El Niño is the opposite event to its “girlish” counterpart. Rather than blowing the trade winds west, winds are weaker and the Pacific Ocean’s surface temperature is much warmer.

No two La Niña and El Niño events are likely to have precisely the same impact on a given region, and event lengths can vary. For example, one rare La Niña weather event lasted three years from July 2020 until March 2023.

How El Niño might influence wildfires

Although nothing is guaranteed when a climate event occurs, there are common, recurring weather impacts that are forecastable. And like La Niña, an El Niño climate event has a meaningful impact on global weather—including a noteworthy, predicted increase in wildfire risk in some regions.

Australia and Southeast Asia: More smoke and bush fires

Weather forecasters are predicting that some areas of Australia may face drought. After having experienced a year of record rainfall and extreme temperatures, vegetation has flourished (4)(5). With withering heat and dried out vegetation, it’s possible that this could create ideal conditions for an increase in bush fires during Australia’s spring and summer, with stronger impacts on Australia’s eastern coast.

Regions in Indonesia and Malaysia are likely to endure similar conditions, depending on where rainfall patterns are most changed. Seasonal agricultural burning that burns out of control and wildfires could then be much worse than in previous years, as was the case in Indonesia during the last El Niño (6)(7).

Latin America: Flooding and drought

Previous El Niño years have brought extreme weather to Latin American countries with a wide range of environmental hazards, varying from flooding to severe drought conditions.

Flood patterns are more common on South America’s west coast, while the Amazon and north-east Brazil are more prone to drought. And though central Chile would normally receive more rain during an El Niño, the impact could be reversed due to climate change-related rainfall reductions.

If drought occurs, Chile and the Amazon could be potential hotspots for severe wildfires in 2023.

Pacific Northwest: Elevated wildfire risk

The U.S. and Canadian Pacific Northwest are generally drier and warmer during El Niño years (8). If vegetation in the Pacific Northwest dries out under extreme heat, there is an increased risk of wildfires in the region. But those conditions may not be in place until later in the summer.

The U.S. National Interagency Fire Center is estimating that there will be above normal fire potential in portions of Washington State, Oregon, Idaho, and Nevada between July and August 2023 (9). But the delay is likely due to cool, wet weather conditions during March and April which reduced the amount of ignitable woodland tinder.

That may change as summer heat arrives, exacerbated by the warming from El Niño. The region experienced higher than normal heat in May, while wildfires in northern Alberta caused unhealthy and even hazardous air quality conditions across western Canada on May 17, 2023.

Poor air quality in western Canada and Montana on May 17, 2023. Source: IQAir.

South Asia: Monsoon disruption

Changing weather patterns can impact India’s monsoon season (10). During past El Niño years, India experienced below average rainfalls and, occasionally, severe drought.

Uncontrolled agricultural burns and forest fires could be intensified by dry conditions, a serious concern given that India has shortcomings in fire preparedness. In 2021, India and Nepal experienced record forest fires that were difficult to control due to limited firefighting resources (11).

Southwestern and Southern U.S.: Wetter conditions likely to prevail

While the Pacific Northwest may experience an increase in wildfire activity during 2023, the opposite may be the case in the American Southwest – at least for the early summer. The risk for significant wildfires is forecast to be normal to below normal.

El Niño usually brings more rainfall to the southern United States, ranging from California to the Southeastern states. Southern California has already experienced a significant wet season that lasted until April – the rain has reduced the amount of potential wilderness fuel for wildfires.

However, if the rains don’t materialize, excess vegetation growth could turn to kindling and the region could experience more wildfires as excess vegetation dries out.

Though there were still dry areas of the U.S. West in May, the multi-year regional drought has been mostly alleviated, with extreme drought lingering mostly from west Texas to Kansas (12).

In a bit of good news, the Atlantic hurricane season will likely be weakened, with fewer predicted named storms and hurricanes likely to occur.

The takeaway

It’s impossible to foresee precisely what a climate event like El Niño will yield. But regularly recurring climate events and their frequently associated chain of regional weather events can help prepare us for severe, adverse health risks from wildfire smoke. Even if trends suggest there will be fewer wildfires in one region, that doesn’t protect that region’s residents from drifting smoke, even continents away.

It’s helpful to prepare for wildfire smoke before a fire actually ignites.

Here are a few ways to arm yourself for any air quality event so you can breathe a little easier:

• Download the free AirVisual app and know what your air quality looks like in real-time, any time of year.
• If poor air quality is affecting your home, run a high-performance air purifier for wildfire smoke.
• And if you have to go outdoors when air quality is poor, be sure to wear a KN95/FFP2 mask.