Welcome to WHIPLASH Weather

Weather patterns are see-sawing from one extreme to another faster and more frequently than ever before, with increasingly deadly consequences. And the phenomenon is coming to places you wouldn't expect

- by PROF BILL MCGUIRE

California is no stranger to wildfires, but January 2025 saw some of the worst yet. Supercharged by global heating, more than a dozen fires raged across the Los Angeles metropolitan area and around San Diego, driven by hot Santa Ana winds reaching speeds of 160km/h (100mph).

Hundreds of thousands of people were evacuated and more than 16,000 homes and other buildings were destroyed – some owned by celebrities, including Billy Crystal, Jeff Bridges and Anthony Hopkins. The fires killed 31 people, but another 400 or so are thought to have died due to indirect effects of the fires, most notably the poor air quality.

While the fires took just a few weeks to do their worst, it had taken years to set the stage for their appearance. For the last decade or so, extreme drought was the order of the day across much of southern California. But then the weather flipped, bringing exceptionally heavy rainfall in 2022 and 2023, which resulted in an explosion of growth across forest, brush and grassland.

Then, in 2024, conditions flipped back again, bringing California's hottest summer on record. This was followed by extremely dry weather in the autumn and early winter, which saw next-to-no rain in downtown LA. By January 2025, there was a huge quantity of tinder-dry vegetation, just waiting for a spark to launch a conflagration and, inevitably, it came.

What made the fires even worse is the fact that, for every 1°C (1.8°F) the planet heats up, the atmosphere is able to absorb seven per cent more water. In 2024, the world was more than 1.5°C (2.7°F) hotter than pre-industrial times. Hotter air can hold more water, so as the temperature climbs, the atmosphere acts like a sponge, sucking even more moisture out of vegetation and soils. This means that when the rain does eventually fall, it's much more intense, which in turn, encourages more plant growth that provides fuel for fires.