U.S. Has Had Most Wildfires Through June in 10 Years, and We're Headed Into the Peak Months

 Jonathan Erdman

Published: June 22, 2021

The number of large wildfires in the United States so far in 2021 is the most through late June in 10 years, with the most active months usually still to come in what could become a record year for fires.

Through June 21, there have been 28,926 large wildfires in the U.S. in 2021, according to the National Interagency Fire Center in Boise, Idaho.

This is about 4,000 more wildfires than usual, and the most wildfires to date in any year since 2011. The NIFC defines a large wildfire as one with a size that's at least 100 acres in timber, at least 300 acres in grass or brush, or requires a larger firefighting response from a helicopter, for example.

The number of large wildfires-to-date in the U.S. through June 21 from 2011 through 2021. The average from 2011 through 2020 was 24,933 large fires through June 21.

On Tuesday, the NIFC bumped up the National Wildland Fire Preparedness Level to 4 on a scale of 1 to 5. This daily index is meant to give perspective to how widespread the current fires are, how dangerous fire weather conditions are, and the availability of firefighting resources.

According to the NIFC's daily report Tuesday, it was the second-earliest date they had elevated the preparedness level to 4 since 1990. It was only the fourth year they had done so in June, joining 2002, 2008 and 2012.

June has been particularly active.

Evacuations had been ordered due to wildfires in at least 17 different locations so far in June, including earlier in the month near the Dalles, Oregon; Spokane, Washington; Globe, Arizona; Reno, Nevada; and Cedar City, Utah.

However, the high number of wildfires so far this year haven't covered as much ground as in recent years.

Just over 1 million acres have been charred so far in 2021. That's only two-thirds of the average to date of just over 1.6 million acres from 2011 through 2020. It's well behind the massive 4.5 million-acre pace from 2011.

(MORE: Where Large Wildfires Are Most Common in the U.S.)

Acres burned by large wildfires-to-date in the U.S. through June 21 from 2011 through 2021. The average from 2011 through 2020 was 1,616,319 acres through June 21.

Why So Many Fires?

As of mid-June, the West was suffering its most widespread drought in over 17 years, according to the Drought Monitor analysis.

The Drought Monitor analysis as of June 15, 2021, with areas of worse drought shown by progressively darker contours of tan and brown.

This massive drought resulted from a combination of a lack of summer monsoon thunderstorms in 2020 followed by a dry winter and spring into 2021.

Meager mountain snowpack melted early and largely evaporated out of nearby soil, rather than recharging rivers and reservoirs. Additionally, vegetation dried out much earlier in the spring.

Then a combination of strong winds, low humidity and searing heat set in later in May and June in the West.

Throw in scattered thunderstorms producing little rain – but shifting winds and lightning strikes – and you have a recipe for starting large wildfires.

Concerning Outlook

We're headed into the peak time of year for wildfires in the U.S.

According to data compiled by NOAA's National Centers for Environmental Information, July and August have been the peak months for both the number of large wildfires and acres burned since 2000.

This is when existing drought and the hottest time of the year combine with summer thunderstorms and vacationers failing to put campfires out properly.

Monthly average number of large wildfires (peach) and acres burned (dark brown) from 2000 through 2020. July and August have typically been the peak months in recent decades.

And there's little good news in the outlook this summer.

NOAA's Climate Prediction Center forecasts dry weather to persist into September in much of the drought-parched West, particularly in the Rockies and Northwest.

Precipitation outlook from July through September 2021, issued on June 17. Areas in darker brown/green indicate increased confidence of a drier/wetter than average July-September period.

Given that, NOAA expects drought to fill in the remaining pockets of the northern Rockies and Northwest not already in drought.

While the arrival of more frequent thunderstorms with the summer monsoon may offer some relief in the Desert Southwest, California's rainy season is still months away.

The longer-term trend is also disconcerting.

According to Climate Central, the western U.S. has now experienced drought in 17 of the past 20 years, based on the Palmer Hydrological Drought Index.

Combined with the long-term temperature trend since around 1980, this is raising the risk of larger, more intense wildfires.

Total acres burned in 11 western states and average temperature in those 11 states from 1980-2019.

Just over 10.1 million acres were burned by large wildfires in 2020, an area larger than the state of Maryland and second only behind 2015, according to the NIFC.

About 87 percent of all wildfires in the U.S. are human-caused.

You can help keep the wildfire threat low in several ways:

-Make sure a campfire is fully extinguished before you leave it.

-Maintain your vehicle and outdoor equipment to prevent sparks from igniting dry vegetation.

-Burn debris safely and never on windy days with low humidity and recent dry weather.

-Learn how to protect your home and build a defensible space around your property.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.