Fire danger: How does weather increase fire risk?

Wildfire season goes year-round for many across the United States, but the peak usually comes between April and June for many across the South and in the fall for California. Let's dive deeper into what conditions could make wildfire become a more significant threat!

Three components help fires propagate: drought or dry vegetation, low relative humidity, and winds. If there is ignition, such as a spark, the fire starts. The three weather ingredients often make the fire grow and become erratic.

Fire ignition can be caused by cigarette butts, a still-burning match, smoldering, a small (controlled) fire pit, a hot tailpipe, or even lightning. Knowing the causes of ignition can help us quickly understand that humans cause 9 out of 10 wildfires in the United States.

The reasons for fires to spread are weather-related. Dry seasonal conditions can lead to drought; climate change is causing some areas, such as California through the Four Corners, to live in a perpetual drought.

During the fall, winter, and spring, the United States is dominated by fronts that can usher much drier air from higher latitudes, especially across the Central Plains and East. But for some places, the summers are also high-risk months as warm temperatures also help fires grow, and it is usually toward the end of the dry season when a drought could be at its worst level.

The wind, well… that’s oxygen. The higher the wind, the more oxygen available to help spread the fire and allow it to grow. This makes a fire behave erratically and brings major problems to firefighters trying to put out fires.

Now that you know how the recipe works, check the weather conditions where you live. If the air is dry, winds are strong, and vegetation is dry, a red flag warning or high fire danger will likely be in place. This is the time to avoid activities involving fires. Something as simple as throwing your still-ignited cigarette out the car's window or leaving your vehicle parked on dry vegetation could ignite a fire. It can quickly grow to leave millions of dollars in damage and deaths.