Last Updated on July 11, 2025

I witnessed some crazy wildfires back when I lived in California. The Atlas and Patrick fires both burned less than 15 miles from my home in 2017. 

As someone who’s lost everything to fire before, it was an incredibly uneasy and tense time. And it only seems to be getting worse – the Canadian wildfires were so bad in 2023 that the smoke reached New York.

Wildfires aren’t always linked to climate change – sometimes they’re started by arsonists, mismanagement, or natural causes. But climate change is definitely making wildfires worse and more frequent – leading to something called fire weather. 

But what exactly is fire weather, and how can we prepare for it? Is there a way to prevent it? Here’s everything you need to know to keep yourself informed, safe, and ready. 

what is the definition of fire weather? 

Fire weather refers to any time the conditions are right for a blaze – typically issued as a warning when an area has been too hot, dry, and windy for substantial amounts of time. Fire weather doesn’t mean there are any actual fires – it simply means there could be. 

According to NOAA, fire weather watch alerts will be issued whenever these three critical elements are met: 

• sustained winds averaging 15 mph or greater 
• relative humidity 25 percent or less 
• temperature 75°F or greater 

When these fire weather conditions are met, the landscape is primed for really disastrous infernos that can be difficult to control and put out.

For instance, The Camp Fire of 2018 moved so quick that it overwhelmed the city of Paradise, killing 86 people, many trying to leave in their cars. 

what are the 5 critical fire weather conditions? 

The five critical fire weather conditions include high air temperatures, low precipitation, low soil moisture, low relative humidity, and gusty winds. When you mix all five of these together, you get ample weather that fuels fires.  

Here’s a deeper dive into each element: 

1. High air temps: Very warm temperatures can strip moisture from easily combustible materials, like grass 
2. Low precipitation: Lack of rain or snow, or in extreme cases, a drought 
3. Low soil moisture: When soil moisture is low, vegetation is likely dry and stressed, making it easy kindling 
4. Low relative humidity: If there’s a lack of water vapor in the air, it makes kindling (grass, brush, etc) easier to burn 
5. Gusty winds: Winds can strengthen flames, should a fire ignite 

how do you prepare for fire weather? 

The best way to prepare for fire weather is to stay on top of weather conditions. Springtime is when most wildfires occur, but secondary fire weather season occurs during fall.

Be mindful that climate change affects wildfires, making them more common and less predictable. Be sure to monitor alerts on your phone and check National Weather Service (NWS)’s fire weather map consistently. 

Another way to prepare for fire weather is to create an action plan, in case there is a fire. You should research and check your location on FEMA’s website to get information about disaster declarations in both the past and present. 

Listen for wildfire evacuation orders and take them seriously: Devise a plan with your family members so you all know where to regroup and meet, should you have to evacuate. 

Having a bug out bag full of supplies is a great idea. A bug out bag can be stashed under the bed, in a closet, or in a car – but it should be somewhere you can easily access.  

Here’s what to pack in a bug out bag: 

RELATED: How to Build An Eco-friendly Emergency Kit 

how can we reduce chance of wildfires? 

Obviously being prepared for the worst is important, but what if we could reduce their occurrence? Good news:There are several ways we can reduce the likelihood of fire weather alerts (and wildfires in general).  

controlled burns 

It may seem counterproductive, but doing controlled burns will help reduce wildfires. Why? Because a planned fire can remove dead grass, fallen tree branches, dead trees, and thick undergrowth – aka, the kindling that fuels wildfires. 

Planned burns are done when weather conditions are not fire weather conditions – and can be properly controlled and monitored. Ash from burnt vegetation also releases nutrients back into the soil, allowing for new vegetation to grow and promoting biodiversity.  

You can learn more about controlled burns via Nat Geo but it’s important to note it’s nothing new – indigenous people have been practicing controlled burns for decades. We can advocate for more controlled burns by writing to our local reps, learning more about them, and simply spreading awareness.

tackling climate change 

By having strong climate policy in place, we can ensure fire weather becomes less common. Voting for people who vow to protect the environment – both on local and national levels – is essential to this.  

Getting involved in your government, emailing and calling your local reps, and volunteering your time at environmental non-profits are all great ways to fight climate change on a collective level.  

On an individual level, taking steps to reduce your own carbon footprint too (like switching to renewable energy and driving less) is also a great idea. And of course, don’t forget to make plastic-free swaps or start composting if you haven’t yet! 

RELATED: 4 Ways to Fight Climate Change as One Person 

creating drought tolerant lawns 

If you live in a state that’s prone to droughts (like California), investing in drought-tolerant landscaping is a great way to reduce risk of fires. Drought-tolerant plants require less water and can be less susceptible to igniting.  

Xeriscaping is worth looking into, as well as planting fire-resistant plants (agave, succulents, red yucca, etc).  

Looking into native plants is also worth checking out, as these plants require less maintenance and tend to be more durable in your specific climate. My friend Shelbi recently turned her lawn into a native pollinator habitat and I’m here for it! 

Do you have any questions on fire weather? Let me know in the comments! 

Occasionally, on a breezy but otherwise pleasant day, a weather alert will pop up on your cell phone or TV. No, it’s no mistake; it’s most likely a notification for fire weather—weather conditions favorable for the ignition and spread of wildfires.

Fire weather can occur in any season but peaks during late-summer and fall when drier air and dry fuels (fallen leaves and dormant trees) are commonplace. Although fire weather is experienced globally, it poses a greater risk to locations like the western United States, Australia, Africa, and the Amazon, which are prone to wildfires.

Conditions That Cause Fire Weather

In order to burn, fire needs three ingredients: heat, oxygen, and a dry fuel source. The following weather conditions conspire to supply these, and spell fire danger because of it.

High Air Temperatures

Very warm temperatures increase evaporation, which in turn strips moisture from easily combustible materials, including grasses, shrubs, trees, dead leaves, and pine needles that act as kindling for wildfires. Sun-warmed fuels also ignite faster, since less heat energy is needed to bring them up to their ignition temperature. 

Low Precipitation

Precipitation dampens the surface of fuels to the point that fire cannot ignite. A lack of rain or snow, or in extreme cases, a drought, does the exact opposite; it dries out fuels, thereby allowing them to combust more easily.

Low Soil Moisture

Soil moisture (the amount of water contained by soil) is a good indicator of “fuel moisture,” or how full of water living plants are. When soil moisture is low, local vegetation is likely dry and water-stressed, which also means it’s more likely to burn. According to a study relating soil moisture to wildfire size in the Southern Great Plains, soil moisture plays such an integral role in fire activity that it outweighs the contributions of warm temperatures and low precipitation.

Low Relative Humidity

When relative humidity (a measure of how much water vapor is in the air) is low, it helps to dry out fuels, making them more flammable. 

Gusty Winds

Should a fire ignite, winds can worsen it in a number of ways. For one, they supply fire with more oxygen, which results in it burning more rapidly. High winds also reduce fuel moisture by increasing evaporation, as well as encourage a fire to spread by physically pushing it and transporting embers ahead of its flaming front.

If you’re watching the weather map, look for low humidity and strong, gusty winds to move in after the passage of a dry cold front (a cold front associated with a dry air mass). Critical fire weather is also commonly linked to high pressure in upper levels of the atmosphere, since these weather features can act as “heat domes,” bringing clear skies, sinking air, very dry air, and above-average temperatures during the warmer months of the year, of course.

Fire Weather Watches and Warnings

Because fire control so heavily relies on weather, NOAA’s National Weather Service (NWS) works in tandem with land management organizations to monitor problematic weather patterns. When several fire weather conditions occur simultaneously, and coincide with dry fuels, the NWS will either issue a fire weather watch or a red flag warning.

Fire Weather Watch

A fire weather watch is issued when red flag criteria might be met in the near future, generally within the next 24 to 72 hours.

Watches give the public and fire crews time to prepare for an elevated fire risk.

Red Flag Criteria

Red flag criteria are threshold wind and humidity values that signal an increased risk of fire danger. Criteria are set by local NWS offices, and vary from region to region, depending on the local vegetation type, topography, drought conditions, and more. At a minimum, the criteria include:

• Winds of 15 miles per hour or greater (measured at a height of 20 feet above ground).
• A minimum relative humidity (usually occurring in the afternoon) of less than 25%.
• A 10-hour fuel moisture (a measure of how much water is held by grass and leaves which take 10 hours to respond to changes in wetness/dryness) of 10% or less.

Red Flag Warning

If a red flag warning is issued, it means that red flag criteria are already being met, or will be met shortly, generally within the next 12 to 24 hours.

Expect any fires that ignite to spread rapidly and become difficult to control or suppress. Under red flag warnings, burn bans will also be in effect.

How Climate Change Is Impacting Fire Weather

If it seems as though you’re seeing more red flag warnings today than in years past, blame climate change. Global warming is actually increasing fire weather season length, or the number of days each year when atmospheric conditions are ripe for fire danger. A study in Nature Communications reveals that between 1979 and 2013, fire weather seasons have lengthened by an average of 19% across one quarter of Earth’s vegetated areas. Zoom in on western U.S. forests, and you’ll find that fire weather seasons there have lengthened by eight days.

This same study also looked at longer-than-normal fire weather seasons. It found that these, too, have become more frequent as a result of climate change—53% more frequent, globally.

Research focusing on California finds that, since the 1980s, the state’s increases in autumn temperature and decreases in precipitation amount to a 20% increase in fire weather indices. If recent trends continue, California could see a 25% increase in its autumn fire weather days by 2100.