We’ve all heard the term ‘La Niña’ thrown around these last few years, with round three now upon us. “Three peat” La Niña’s are quite rare, with the most recent ones happening between 1954-57, 1973-76, and 1998-2001. But with the rapid movement in climate change, these rare events can become more common. So what does this all actually mean? And how will it affect this year’s Spring and Summer?
What is La Niña?
La Niña, and its counterpart El Niño, have a strong influence on Australia's weather each year. Both are part of a natural climate cycle called the El Niño-Southern Oscillation, or "ENSO" — a weather pattern that occurs in the Pacific Ocean driven by a circulation called the Walker Circulation.
During La Niña, the Walker Circulation picks up warm water near Australia, carries it east across the ocean towards South America where it descends, and pushes cold, deep water from South America westward towards Australia. El Niño occurs when this circulation is weaker or reversed. While we can't prevent these phenomena, our contribution to climate change does affect their severity and frequency.
La Niña's Impact on Australia
No two La Niña events are identical, and the effects vary depending on where in Australia you live. However, there are some consistent patterns:
Increased Rainfall
Grab your umbrella — La Niña brings above-average Spring rainfall across Australia, especially in the east and north, which can continue into early Summer. In January 2021, rainfall across NSW was 41% above the 1961–1990 average*. The chance of widespread flooding increases, particularly on the east coast. If you live in a flood-prone area, it's worth having a plan in place.
Temperature Changes
La Niña's rainfall and cloud cover reduces average maximum temperatures for those south of the tropics. North of the tropics, the cloud cover acts as an insulator, bringing warmer-than-average minimum temperatures.
Changes in Heat Extremes
During Spring and Summer, southern locations like Adelaide and Melbourne are likely to experience fewer extreme heat days, but may see an increased frequency of prolonged warm spells. In South New South Wales and North Victoria, warmer nights mean fewer frost days than average.
More Tropical Cyclones
La Niña increases the risk of tropical cyclones, particularly in Queensland — twice as many make landfall compared to El Niño years. This brings strong winds, high seas, and heavy rain that raises the likelihood of flooding and major damage.
Earlier Monsoon Onset
The monsoon season in tropical Australia is typically brought forward by two weeks during La Niña. The Northern tropics experience above-average rainfall early in the wet season.
What La Niña Means in Practice
After years of scorching heat, La Niña brought welcome cooler conditions for many. Some farmers benefited from the rainfall — the beef industry in Queensland particularly, as wetter summers increase pasture growth and cattle weight gain.
However, the last few La Niña cycles have produced some of the wettest conditions since Bureau of Meteorology records began in 1900. Repeated flooding across consecutive years has had serious consequences for communities that haven't had time to recover between events. As one South Lismore resident described the ongoing threat: "very stressful."*
Fortunately, the most recent La Niña phase was not as powerful as the double event of 2010–2012, which caused catastrophic cyclones and flooding. Models indicated that La Niña would return to neutral conditions in early 2023.*
For WA and most of the NT and SA, ENSO effects are less pronounced. Those along the east coast — especially in Queensland — experience the most significant changes. Heat waves can still occur during La Niña, but they tend to be less intense, and the wetter conditions reduce the risk of bushfires.
ACCIONA's Role in Australia's Climate Response
La Niña and El Niño events are likely to become more frequent and intense as global greenhouse gas emissions continue to rise. Reducing emissions is the most effective way to stabilise weather patterns over the long term.
ACCIONA is helping Australia combat climate change through investment in renewable energy infrastructure and sustainable development. The Waubra Wind Farm in Victoria — one of the largest when built in 2009 — has been generating 192MW of clean energy for over 12 years, powering up to 138,000 Australian homes annually.
ACCIONA Energía's MacIntyre Wind Farm Precinct in Queensland, at 1,026MW, is one of the largest onshore wind farms in the Southern Hemisphere, highlighting how rapidly the industry has grown over the past decade. The Mortlake South Wind Farm adds a further 117,000 homes' worth of green energy, preventing approximately 532,000 tonnes of CO₂ from coal-fired power stations each year.
These projects are practical steps towards the greener, more sustainable future that will help stabilise Australia's climate over the long term.