There was an increased risk of fire on parts of the Hawaiian islands Thursday because of low humidity and wind gusts, just three weeks after strong winds whipped devastating blazes over west Maui, forecasters said.

The National Weather Service issued red flag warnings to the leeward sides of all the islands, which means there's a danger of wildfires spreading. But forecasters said winds won't be nearly as strong as they were on Maui on Aug. 8, when at least 115 people perished in the deadliest wildfires in the U.S. in more than a century.

"The combination of dry fuels, strong and gusty winds and low humidity levels will result in high fire danger and an the risk for extreme fire behavior," the weather service said Thursday. 

Dry vegetation and winds could fuel any fires that start

The weather conditions Thursday mean any fire that sparks or has already started could spread rapidly, but it doesn't necessarily mean new fires will start, AccuWeather meteorologist Haley Taylor told USA TODAY.

A difference in pressure coming from opposite sides of the islands is causing the high winds, Taylor said. Low humidity was expected midmorning to late afternoon Thursday, while winds were forecast at 15 to 30 mph with gusts up to 40 to 50 mph.

The strongest gusts were expected "downwind/ leeward of the higher terrain" on Maui and the Big Island, the weather service said.

"During this time, any fires that start will likely spread rapidly and be very difficult to control," the agency said, warning people to avoid burning outdoors.

'Our hearts are broken':Maui officials near end of search for wildfire victims

The conditions were similar to conditions earlier this month that allowed fire to consume Lahaina, Taylor said, but wind speeds are a key difference.

"This isn't going to be the same exact thing as what happened earlier in August. It's going to be similar, but it's not going to be as extreme," Taylor said.

What caused the wildfires that decimated Lahaina?

It's not clear exactly how the fires started, but experts have said a combination of extremely dry vegetation, strong winds from Hurricane Dora, low humidity and drought set up the perfect conditions for fire to quickly get out of control.

Winds that day topped 60 mph, the weather service said.

Wildfires have quadrupled in Hawaii in recent decades as rainfall has significantly decreased over the past 30 years.

The County of Maui has filed suit against the Hawaiian Electric Company, claiming its failure to shut off power despite warnings from the weather service contributed to the disaster.