Updates from Environmental Experts

What's Causing the California Fires to Spread So Quickly?

Amalia Helen
California Fire Image

At the time of writing, the Kincade Fire in Northern California alone has grown to 74,000 acres and is only 15% contained. The Tick Fire continues to burn near Santa Clarita in the South of the state, moving across the border into Mexico, a new fire has broken out in San Francisco, and the Getty Fire has forced many - including the likes of LeBron James and Arnold Schwarzenegger - to leave the area.

Thousands of people, have been forced to abandon their homes, and don’t know what they’ll come home to. Schools have been shut in response to the growing threat of the flames and worsening air quality. The Governor of California has declared a state of emergency and claimed that the size and extent of the blazes they are dealing with is unprecedented.

Wildfire Impact Spreads Much Further Than the Flames

Approximately a million Pacific Gas and Electric customers have been left without power up and down the state, and the impact of toxic-related fire smoke is affecting even more. 

As our CEO Ran Korber explains, “fire-related pollution spreads across borders and lingers for a considerable amount of time depending on weather and climate factors.”  This means  fire-related air pollution can be extremely dangerous even if a person is far from the actual fire source, or the fire has already passed.

An Ongoing Tragedy as Wildfires & Smoke Impact Affects Millions

See a visual representation of the dynamic fire-related air pollution as captured by BreezoMeter's live heatmaps:  


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We also recorded extremely low air quality levels at specific locations over the last few days:

Kincade Fire App

Where to Get Air Quality Information?

The California fires have triggered a surge of interest among those living nearby who are interested in tracking the air they’re breathing, as well as discussions around air quality data sources and their reliability.


John Lily

As the extreme nature of these fires and power outages in the region prevent other air quality data sources from maintaining a reliable service, BreezoMeter continues to accurately notify residents of new active fires and the air quality levels in their surrounding area .

BreezoMeter adopts a unique multi-data layer approach and deploys sophisticated algorithms, computational models and machine learning technology which means we are able to continue reporting even as local sensors become damaged by smoke or go offline due to power cuts. 

Are These Fires Really Unprecedented?

The United States is no stranger to wildfires, official reports estimate that approximately 270,000 wildfires occurred in 2018 alone. Interestingly, trend lines indicate that the occurrence of brush, grass and wildland fires is actually decreasing.


Fire Graph.

NFPA Research Source

However, wildfires on the US West Coast do seem to be getting larger as time goes by.  As reported by the Washington Post, the average wildfire in the 1980s and 1990s burned between 40-80 acres of land - in the 2010’s, we saw a number of years when the average fire reached more than 100 acres in size. The largest single wildfire recorded in California was the Mendocino Complex fire which burned through 439,123 acres between July and November 2018. To put things into context, the Kincade fire alone has already burnt through 70,000+ acres after only 5 days.

That said, at any given time, there are other wildfires happening around the world. For example, the devastating Amazon rainforest fire (which by the way is still ongoing) has so far burned through 2,240,000 acres and huge wildfires in Russia’s Siberian Province continue.

The Diablo & Santa Ana Wind Effect in California

Fierce and dry winds have undoubtedly contributed to the rapid spread of the fires and smoke across the West coast of the US and Mexico this week. Diablo winds are common in Northern California in the winter and autumn seasons and typically bring warmer weather and drier air with them. Further, Diablo winds are at their most dangerous when the vegetation is at its driest. In South California, these warm winds are referred to as the Santa Ana winds

The combination of dry and warm conditions, together with extreme gusts of up to 93mph  is creating the perfect conditions for the fires to spread and making the task of the firefighters a lot more challenging.

Rising California Temperatures 

Broader climate change trends could also be contributing to the larger and more deadly spread of wildfires on the West coast. A study conducted by Columbia University in 2016 found that temperatures in Western forests have increased by about 2.5 degrees since 1970. In turn, this contributed to more burning than would have happened with no temperature change. And California is getting hotter - in July 2018, the state recorded their highest minimum temperature statewide for any month since 1895

Unfortunately, the climate change impact on the size and nature of forest fires is not confined to the US West Coast. There is now a significant body of research that suggests the likelihood and impact of wildfires may now be greater as a result of climate change in many places across the world

The Devastating Smoke Effect

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High levels of particulate matter present a significant threat to public health and, as the EPA reports, exposure over just a few days could be linked to premature mortality and aggravation of pre-existing conditions, especially respiratory and cardiovascular diseases.  

As news outlets focus on the immediate danger posed by the California wildfire flames, it is important the broader population remain alert to the broader impact of far-reaching and lingering smoke and take measures to reduce their exposure. Any forest fire will emit hundreds of different pollutants and increase concentration levels of PM2.5 and PM10 in the air. 

Looking After Your Health during a Wildfire Outbreak


  • Stay up to date with air quality at your location and be aware of any new fire outbreaks with BreezoMeter’s fire alerts.

  • Stay indoors and close windows to reduce exposure to ambient air pollution. Population groups that are elderly, pregnant, immunocompromised or asthma and COPD sufferers should avoid being outdoors as much as possible.

  • Reduce physical activity to reduce the dose of inhaled air pollutants.

  • Make use of an indoor air purifier.

  • Limit the indoor air pollution you generate (Smoking cigarettes, gas, propane and wood-burning stoves and furnaces, spraying aerosol products, frying or broiling meat, burning candles and incense, and vacuuming all increase particulate matter in the air).

  • Wear a respiratory protective mask

  • Stay up to date with air quality at your location.

You can also refer to the guidance offered by the US EPA for specific and comprehensive health advice.

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