Fire Weather Crossover?

You might’ve heard the term ‘fire weather crossover’ thrown around during fire season, but what does it actually mean?

A crossover happens when the air temperature (°C) and the relative humidity (%) are the same number, for example, 32°C and 32% humidity. When this occurs, or when they get close, conditions are extremely dangerous for bushfires.

At that point, the air is hot and dry, and the vegetation around us loses moisture fast, becoming tinder ready to burn. Add a bit of wind, and fires can start easily and spread rapidly.

Crossover days are often a signal for crews to be on high alert. For the rest of us, it’s a reminder to be prepared:

✅ Delay any planned burning.
✅ Keep machinery and spark risks to a minimum.
✅ Have your bushfire plan ready and stay informed via QFD warnings.

It’s not just about numbers; crossover (or near) conditions mean the landscape is primed for fire. A small spark on a day like this can quickly become something much bigger.

Stay safe, stay alert, and keep an eye on the weather; it tells us more than we often realise.