A fire danger rating is frequently read as a forecast that a fire will occur. It is not. Under the Australian Fire Danger Rating System, a rating describes how dangerous a fire would be if one were to start, and each of its four levels carries a specific instruction to the public. This article sets out those levels in the words the fire agencies use, explains what the rating is built from and where it is published, and distinguishes it from the warnings issued once a fire is burning. The decision helper below applies the same instructions to the rating for the day and the place in which a reader expects to be.

The four levels, in the agencies’ words

The Tasmania Fire Service describes the system as national and consistent: the same levels, carrying the same meaning, apply across Australia. There are four levels, and a fifth state in which no rating is issued. Each is set out below as the Tasmania Fire Service words it, with the instruction first and the description of conditions second.

1. No rating. On days of minimal risk, no rating is issued. The Queensland Fire Department notes that a white “no rating” bar is shown on those days. Fires may still start, but they are unlikely to spread in a fast or threatening way. The absence of a rating is not a declaration that fire is impossible, and it is the most suitable day on which to make or review a bushfire plan.

2. Moderate: plan and prepare. Most fires can be controlled under these conditions. The instruction is to plan and prepare, to stay up to date, and to be ready to act if a fire occurs.

3. High: be ready to act. Fires can be dangerous. The instruction is to be ready to act, which in practice requires a household to have decided in advance what it will do if a fire starts, rather than deciding on the day.

4. Extreme: take action now to protect your life and property. Fires will spread quickly and be extremely dangerous, and homes may not withstand them. The instruction is immediate. A person who has not prepared to the highest level should go to a safer location well before a fire has any impact.

5. Catastrophic: for your survival, leave bushfire risk areas. At this level, lives are likely to be lost, and homes cannot withstand fires in these conditions. The instruction is to leave bushfire risk areas, and the Tasmania Fire Service is specific about timing: leave early in the morning or the night before.

Two observations follow from the wording. First, the instructions escalate from preparation to action to departure, and only the highest level instructs the public to leave regardless of how well a home has been prepared. Second, the instructions apply before any fire exists. A Catastrophic rating on a day without a single fire still means that the advice is to be out of bushfire risk areas.

What the rating is built from

A rating is not an observation of fire activity. According to the Tasmania Fire Service, it is calculated from forecast weather, vegetation and fuel. The result describes the potential danger should a fire start in those conditions.

Three consequences follow for the reader:

1. A rating can be high on a day on which no fire is burning anywhere nearby, because it measures conditions and not events.
2. A rating can change from one day to the next as the forecast changes, which is why it is issued daily.
3. A rating is issued for an area, and it does not replace a household’s own attention to its immediate surroundings.

The national consistency of the system matters here as well. A rating of Extreme carries the same instruction whether a reader is at home in one state or travelling through another, and a person familiar with the system in one jurisdiction may rely on the same meanings elsewhere.

Where to find today’s rating

The Queensland Fire Department states that ratings were originally published by the Bureau of Meteorology and are updated daily. State and territory fire agencies carry them for their own areas.

The practical requirement is straightforward. During the high-risk period, the rating should be checked every day, and on a day of travel it should be checked for each area through which the journey passes, not only for the point of departure. A rating that was Moderate at home in the morning says nothing about the rating in a district two hours away.

Roadside fire danger signs are a familiar reminder that the system exists. They are not a substitute for the published daily rating for the area concerned.

Three habits make the daily check reliable:

1. Check at the same time each day. A fixed time, such as the evening before or first thing in the morning, prevents the check from being forgotten on a busy day.
2. Check for tomorrow as well as today. A Catastrophic rating calls for departure the night before or early in the morning, and that instruction can only be followed if the rating has been seen in time.
3. Check every area on the route. A journey through several districts may pass through more than one rating on the same day.

Ratings and warnings are different

The rating and the warning answer different questions, and confusing them is one of the more consequential errors a reader can make.

1. A fire danger rating concerns potential. It describes how dangerous a fire would be if one started, and it is issued in advance, whether or not any fire exists.
2. A warning concerns an actual fire. The Tasmania Fire Service advises that when a fire is burning, the public should follow the advice issued under the Australian Warning System.

The rating therefore sets the conditions under which a household’s plan should operate, and the warning tells the household what a specific fire requires of it. Once a fire is burning, the Tasmania Fire Service’s advice is to follow the warning issued for that fire. In an emergency, call 000.

Total fire bans

Total fire bans are a separate instrument. They are declared by state and territory fire agencies, and the restrictions that apply during a ban are a matter for the agency concerned.

This article does not state when a ban is declared or what it prohibits. Those matters differ between jurisdictions, and the sources consulted for this article do not set out how bans relate to the ratings. A reader should check the relevant state or territory fire agency on any day of elevated danger for whether a ban is in force, in the same way that the rating itself is checked.

A plan that uses the ratings as triggers

The Tasmania Fire Service recommends that ratings be used as triggers within a bushfire plan. The principle is that decisions are made in advance and tied to a level, so that on a difficult day a household is following a decision rather than making one under pressure.

A plan built on that principle would set out, at a minimum, the following:

1. At Moderate. The checks the household will carry out, including the review of the plan itself and the preparation of the property.
2. At High. What the household will do if a fire starts, where it will go, and who will make the decision.
3. At Extreme. Whether the home has been prepared to the highest level. If it has not, the plan should state that the household will go to a safer location well before a fire has any impact, and where that location is.
4. At Catastrophic. The arrangements for leaving bushfire risk areas the night before or early in the morning, including where the household will stay.

Preparation of the property is part of the plan at every level, and a good deal of it is ordinary maintenance carried out before summer. Gutters are a common example, since they collect leaf litter and other material over the year. A reader considering work on them may find the thinker guide to gutter upgrades worth doing a useful starting point, while noting that the guide concerns the house generally rather than bushfire preparation specifically.

The Tasmania Fire Service also asks that the plan extend beyond the principal residence. Places where a household stays over summer, such as a shack or a campsite, require the same triggers. A family that has a clear plan at home and none for a holiday property has, in effect, a plan for part of the summer only.

Finally, a plan of this kind is most useful when it is written down and discussed with everyone in the household. A rating gives notice. It does not give time to agree on decisions that should already have been made.

Decide before the day

The system is designed so that its instructions can be acted on in advance. The four levels, in summary, are as follows:

1. Moderate: plan and prepare.
2. High: be ready to act.
3. Extreme: take action now to protect your life and property.
4. Catastrophic: for your survival, leave bushfire risk areas.

Each of those instructions is easier to follow when the decision it requires has been made beforehand. The rating for the day should be checked daily during the high-risk period, for each area in which a person will be, and if a fire is burning, the warnings issued for that fire are the advice to follow.

This article provides general information about the national rating system. It is not emergency advice, and it does not replace the advice of the relevant state or territory fire agency.

Sources: Australian Fire Danger Rating System Explained, Tasmania Fire Service (https://www.fire.tas.gov.au/fire-danger-rating/explained/); Monitor Fire Danger Ratings, Queensland Fire Department (https://www.fire.qld.gov.au/prepare/bushfire/fire-danger-ratings)