By the close of southern winter 2026, the Australian bush is carrying a surface fuel load that has not accumulated at this scale in a generation. Three consecutive La Niña wet seasons, the first back-to-back-to-back sequence since 1998 to 2001, dropped well above average rainfall across New South Wales, Victoria, South Australia and Tasmania in 2020-21, 2021-22 and 2022-23. The grass, leaf litter and understorey growth that followed is now curing as soil moisture eases and daytime temperatures climb. The Bureau of Meteorology's June 2026 Climate Driver Update is the live, authoritative read on where the climate system is heading, and the pre-season signal entering the 2026-27 fire season is the most significant compound climate-fuel signal since 2019-20.
That framing is careful on purpose. The 2019-20 Black Summer was, in the words of the Royal Commission, "in many respects, a worst-case scenario" [1]. It burned more than 18.6 million hectares, destroyed more than 3,000 homes and killed 33 people nationally, the most extensive bushfire season in modern Australian records [1]. This article is not forecasting a repeat. It is reading the pre-season signal that climate scientists, fire agencies and emergency services are weighing, and saying plainly that the prudent household response is to prepare to a Black Summer standard, because the combination of fuel and climate drivers beneath the 2026-27 calendar is the strongest combination agencies have seen since the season that produced Black Summer.
How three La Niña seasons built a fuel load
To read the 2026-27 risk, separate two things. The compound climate-fuel picture has two halves: a heavy surface fuel load, and a climate-driver outlook shifting from wet toward neutral or dry. Either one alone would be manageable; together, they are why fire agencies are briefing early.
Australia's fire behaviour is governed by fuel, weather, topography and people. The CSIRO and Bureau of Meteorology's most recent State of the Climate report, published in November 2024, documents that Australia's climate has warmed by approximately 1.5 °C since national records began in 1910, and that the number of days each year with a Forest Fire Danger Index in the "Very High" or higher category has trended sharply upward across southeastern Australia since the 1990s [2]. Warming does not have to be extreme for fire behaviour to escalate on a heavy fuel load. An average fire-weather day on a tall, dry, continuous grass sward can produce fire behaviour that runs faster than firefighters can outflank on foot.
The distinction between grass fire and forest fire matters here, because the two behave differently and the 2026-27 risk is dominated by the first. Grass fires can travel at rates of spread exceeding 25 km/h, faster than most forest fires and well above the speed at which a person can evacuate on foot without a vehicle [3]. A forest fire tends to move more slowly through the canopy and the heavier fuels beneath it, but the radiant heat, ember throw and tree collapse make it lethal at closer range. The compound climate-fuel picture for the coming summer is that the grass is the fast surface threat, while the forest understorey and litter layer in NSW, Victoria, Tasmania and the Adelaide Hills is the slower but deeper crown threat if the season runs hot.
The Bushfire and Natural Hazards Cooperative Research Centre's legacy research program identified three surface-fuel variables as the strongest predictors of grass-fire rate of spread and intensity across southeastern Australia: fuel load measured in tonnes per hectare, fuel continuity (the absence of gaps that would slow a fire front), and grass curing rate, the percentage of the sward that has dried from green to golden [4]. Three consecutive wet seasons maximise the first two. The third, curing, is now accelerating as the 2026-27 season approaches, and that is the mechanism by which wet years become dangerous fire years. The CRC and CSIRO modelling flagged, even at the end of the triple-dip, that surplus fuel would still be available for ignition in subsequent seasons if a single average summer failed to reduce it [4].
The climate-driver signal: from wet to watch
The Bureau of Meteorology has reorganised its climate-driver communication in recent years. The legacy ENSO Wrap-Up and Model Summary pages have been retired; the agency's current authoritative hub is the Climate Driver Update, found at /climate/enso/, with seasonal rainfall and temperature outlooks at /climate/outlooks/ [5][6]. For an article read in mid-2026, the live Climate Driver Update is the source of record for whether the equatorial Pacific is in a neutral, El Niño or La Niña state, and what the bureau's outlook is for the coming months.
What can be said with confidence, on the verified record, is this. The triple-dip of 2020-21, 2021-22 and 2022-23 is documented in BoM's historical archive, and a fourth-year La Niña watch was declared in 2023 [5]. The current state of the system, whether neutral, a developing El Niño, or continued neutral, is the single most important fact to verify before relying on any specific seasonal fire-potential call. A responsible 2026-27 outlook reads the Climate Driver Update on the day it is published and updates accordingly, and readers should do the same.
AFAC, the National Council for Fire and Emergency Services, coordinates the formal mechanism by which BoM signals and jurisdictional fuel-load assessments are combined into the Seasonal Bushfire Outlook for southern Australia, typically released in September or October each year [7][8]. The outlook is the most-cited pre-season synthesis in Australian media coverage of fire risk, and it is the document fire agencies read into their public warnings. Past outlooks covering the 2020-22 and 2022-23 periods repeatedly flagged well-above-average grass fuel across southeastern Australia, and a comparable 2026 reading should be expected if the fuel-load observations confirm what the prior three wet years would predict [7].
Two climate drivers beyond ENSO matter for the coming summer. The Indian Ocean Dipole modulates winter and spring rainfall over southern and eastern Australia, with a negative IOD reinforcing wet conditions and a positive IOD typically suppressing them. The Southern Annular Mode influences the position of the westerly storm track and the frequency of cold fronts across the southeast. Both are tracked on the BoM Climate Driver Update page and feed into the bureau's integrated outlook.
The underlying warming matters regardless of which way the next phase swings. The State of the Climate report notes that cool-season rainfall has declined over much of southeastern Australia in recent decades, even as heavy rain events have become more intense [2]. That is the pattern that produces tall grass growth in winter followed by hot, dry summers, because the heavy events dump enough water to drive biomass accumulation while the drying trend between events lets the fuel cure. The compound climate-fuel picture is not a single anomaly. It is the system doing what a 1.5 °C-warmed climate does.
What the compound signal means for fire behaviour
The transition from a wet to a dry climate-driver phase, on a heavy, continuous fuel load, raises two distinct risks that households should treat separately: fast-moving grass fire in the open country, and weeks of smoke exposure across urban and regional airsheds.
The 2019-20 Black Summer provides the reference. Peer-reviewed research led by Borchers Arriagada and colleagues, summarised by NSW Health, attributed more than 400 excess deaths and more than 4,000 excess hospitalisations for respiratory and cardiovascular causes to bushfire-smoke exposure across NSW, Victoria, the ACT and Queensland during that season [9]. The dominant pollutant was fine particulate matter, PM2.5, which penetrates deep into the lungs and enters the bloodstream. Children, older adults, pregnant women, and people with asthma, COPD or cardiovascular disease are the most exposed groups, and the public-health guidance during a smoke event is to stay indoors with windows and doors closed, run air purifiers on recirculate, and follow state health authority advice in real time [9].
The fire-behaviour risk is the more visible half. Grass fires on a heavy, curing sward can reach a property line before a Total Fire Ban is declared, before an emergency warning is issued, and before a household has finished packing a car. The Country Fire Authority in Victoria is explicit on this point: on days of Total Fire Ban, well-prepared households should still leave and leave early if fire is in the area, rather than attempt to defend a property that has not been actively prepared [3]. That rule is the single most important behavioural guidance to take from the pre-season signal.
A further compounding factor is the Royal Commission's own warning. The Commission concluded that "we cannot treat [Black Summer] as a one-off. Climate change is increasing the risk of more frequent and more intense fire weather events" [1]. That observation was made in 2020, and the climate data since then has only strengthened the case. The 2026-27 season is not a guarantee of Black Summer outcomes. It is the next test of whether the country has internalised the lesson the Commission tried to teach.
Preparing at the household level across the four states
Preparation in 2026-27 is a four-state problem, because the jurisdictional services differ in authority, terminology and public-facing tools. The advice below draws on each agency's official public guidance, and households should follow the lead combat agency for their state.
In New South Wales, the NSW Rural Fire Service is the combat agency for bushfire across most of the state outside the Sydney basin and other urban zones served by Fire and Rescue NSW. RFS is also the world's largest volunteer fire service, with more than 70,000 members, the bulk of whom deploy across the October to March fire season [10]. The agency's official Bush Fire Survival Plan workbook sets out the prepare-act-survive framework: decide in advance what you will do on a bad fire day, plan what you will take, know which road you will leave by, and have a backup. The Fires Near Me app is the most widely used bushfire-information tool in NSW and should be installed with notifications enabled before the season starts [10]. For 2026-27, the dominant surface-fuel threat across western and southern NSW is grass fire, and RFS distinguishes grass-fire and bush-fire risk separately for that reason.
In Victoria, the Country Fire Authority's Plan and Prepare portal is the official entry point for household and farm bushfire survival plans, including the five-minute Fire Ready Kit and the Red Cross 3 Property Bushfire Survival Plan [3][11]. The CFA's Bushfire Basics page defines the four Fire Danger Rating categories: Moderate, High, Extreme and Catastrophic, and the behavioural triggers associated with each. A Catastrophic day in CFA country is, by long-standing agency rule, a day to be away from the property in the morning, not to be defending it. CFA is explicit that three consecutive wet seasons produce a tall, continuous grass fuel load across central and western Victoria, the pattern observed after 2020-23 [3][11].
In South Australia, the Country Fire Service is the lead combat agency for bushfire outside the MFS-designated Adelaide metropolitan area [12]. The districts most exposed to grass and forest fire risk after consecutive La Niña years are the Adelaide Hills, Kangaroo Island, the Mount Lofty Ranges, the Mid North and the South East. CFS coordinates with BoM and the SA Department for Environment and Water on pre-season briefings, and the agency's bushfire survival plan guidance should be the household reference for any SA resident in or near those districts [12].
In Tasmania, the Tasmania Fire Service is the lead bushfire response agency and publishes the Tasmanian Fire Danger Rating System and Alert advice [13]. Tasmania experienced significant bushfires in 2018-19, which devastated forested areas in the state's south-west and Central Highlands, and again in 2022, both recent analogues for what a heavy fuel load plus a dry summer can produce. TFS has advised that bushfire risk in the Tasmanian bush is heavily dependent on fuel loads that accumulate during multi-year wet periods, and the 2026-27 season should be read in that light [13].
Across all four jurisdictions, the practical preparation steps line up. Write a written plan, not a mental one. Decide in advance whether you will leave early, or, only if you have an actively prepared, defendable home, stay and defend. Pack a go-bag with water, medication, important documents, phone chargers and a battery-powered radio. Know two routes out, because one will be closed. Talk to your neighbours, because local knowledge of road conditions and back gates is often what saves time on a bad day. Maintain the first 20 metres around your property so that leaf litter, bark and long grass do not form a continuous fuel bridge to the house.
For respiratory preparation, the parallel task is to make the home smoke-tight before the season arrives. NSW Health's public guidance recommends sealing obvious gaps, having HEPA-filtered air purifiers on hand, and knowing which rooms can be closed off to create a clean-air refuge during multi-day smoke events [9]. Smoke events in 2019-20 lasted weeks in some regional centres; planning for that duration is the right scale.
What to watch between now and southern spring
This article is a snapshot of a moving situation, and a small number of live data points will tell any reader whether the pre-season signal has strengthened or eased. First, the BoM Climate Driver Update at /climate/enso/, updated fortnightly, which is the authoritative read on the current ENSO state and the bureau's outlook [5]. Second, the BoM long-range rainfall and temperature outlook at /climate/outlooks/, which translates the climate-driver signal into a probabilistic view of the coming months [6]. Third, the AFAC Seasonal Bushfire Outlook for southern Australia, typically released in September or October, the formal synthesis fire agencies read into their public warnings [7]. Fourth, for NSW residents, the RFS Fuel Load Index and the Fires Near Me app, which translate state-level fuel observations into location-specific risk [10]. For Victoria, the CFA's Total Fire Ban days and Fire Danger Rating system should be tracked through the agency's official channels [3][11].
The compound climate-fuel picture entering 2026-27 is, in the language fire researchers use when briefing each other, the most significant pre-season signal since 2019-20. The signal is not a prediction. It is a warning to be ready, and to read the next update when it is published, because the country that prepares to a Black Summer standard in October 2026 is the country that will get through the season that follows.