From dry heat to torrential rain — why abrupt shifts in weather are the new norm
In simple terms, weather whiplash is becoming more common because a warmer atmosphere can hold more moisture.
Record-breaking extremes in temperature and rainfall are happening more regularly, with 2025 set to be one of the warmest years on record. Current levels of warming are already driving more frequent weather extremes, including heatwaves, intense rainfall and droughts.
According to Gallagher Re Chief Science Officer Steve Bowen, weather whiplash increases the ferocity of wildfires when very wet periods — which promote rapid growth of vegetation — are followed by very dry and hot periods.
In areas prone to wildfires, dramatic swings from wet to dry influence how much dry vegetation is available to fuel the spread of fire. The vegetation that heavy rainfall promoted dries out during arid spells, providing tinder for wildfires. When combined with strong winds and sloping terrain, the combination of dry vegetation and hot, dry conditions can see wildfires move at astonishing speeds — as fast as 20 mph.
The weather whiplash pendulum can swing the other way as well. Wildfires leave behind burn scars made up of ash and other loose debris, creating an elevated risk of mudslides and landslips if affected regions experience heavy rainfall.
An abrupt shift from a period of drought to heavy precipitation also can heighten the risk of flash floods. Dry soils become hard and compacted, resulting in more surface runoff, which can overwhelm drainage systems and waterways when the rain finally comes.
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Going from one extreme to another in such quick succession can really amplify the potential wildfire losses that can be incurred.
Steve Bowen, chief science officer, Gallagher Re
Far-reaching effects
Shifts from one weather extreme to another can have additional substantial consequences, making communities more vulnerable.
For example, weather shifts can lead to water scarcity. Regions experiencing long periods of drought are less able to capture and replenish water stores, because torrential downpours are too much for aging drainage systems to handle. As a result, drinking water can become contaminated.
The long drought in Southern California contributed to a lack of water pressure that's said to have hindered firefighting efforts during the 2025 Palisades Fire.1
And trees stressed by heat and drought are becoming more susceptible to damage and pest infestation, impacting their vulnerability to both wildfire and floods. For example, in North America, Europe and parts of Asia, bark beetles attack weakened forests, adding more dry fuel to the landscape and weakening nature's flood defenses.
Building resilience amid more unpredictable climate extremes
For businesses and communities, weather whiplash adds a dimension that needs to be factored into disaster preparedness and loss mitigation strategies.
Since 2017, many California school districts pay to wrap buildings with fire-protective aluminum sheets when the threat of wildfire is high. Keeping vegetation under control is another key loss control strategy, with schools employing novel methods, such as bringing in goats to snack their way through the undergrowth.
One of the main lessons, according to Bowen, is that the past is not always the best indicator for how events might play out in the future.
"Being cognizant of these shifts in weather is becoming much more important as we see the influence of climate change in day-to-day weather patterns," he says. "It's a real concern that we're having to pay much more attention to today."
Building resilience to more extreme wildfire and flood events in the future will require investment and a collaborative approach between the public sector, business and communities. Nature-based defenses — or green infrastructure — are among the more cost-effective and powerful solutions, an area that's attracting more attention and investment.
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Published in December 2025
