Firefighters battle a fire near railroad tracks northeast of Hermiston on Wednesday afternoon.

HERMISTON — A series of fires along railroad tracks near Hermiston kept firefighters busy Wednesday afternoon.

The five fires, which started at roughly 11 a.m., burned between Walls Road and Highway 730 northeast of Hermiston. Umatilla County Fire District Chief Scott Stanton said the cause of the fires were under investigation, but looked like they had likely been sparked by a train.

On Wednesday afternoon about 3 p.m. Stanton was supervising mop-up operations at the fires. He said they were not large — the one he was at looked to be about 5 acres.

“They were in heavy brush and trees, not just grass, so that made it more difficult,” he said.

Umatilla Rural Fire Protection District, Echo Fire Department and Boardman Rural Fire Protection District assisted in the effort.

Stanton cautioned area residents to be extremely careful during what he predicts will be a dangerous fire season.

“The grasses are cured and ready to burn,” he said. “It’s going to be a windy day tomorrow, and it’s getting hot and dry.”

The National Weather Service in Pendleton also warned of an increase risk for wildfires Thursday.

The agency reported thunderstorms were likely Wednesday evening over central and eastern Oregon and portions of central Washington. Then winds will increase over the area Thursday. The gusts and the low humidity will lead to “red flag conditions.”

The red flag warning is for Thursday afternoon until 10 p.m.

Westerly winds of 15 mph will increase to 25 mph, and humidity will be 15-20 percent. “Any fires that develop,” according to the Weather Service, “will likely spread rapidly.”

The Weather Service also advised against outdoor burning.

During fire season, people can do their part by following rules for controlled burns and campfires, keeping their vehicles well-maintained, clearing flammable brush from around structures and not being careless with fire hazards, such as cigarettes and fireworks.

Fire season is also smoke season. On Wednesday Senators Jeff Merkley and Ron Wyden introduced a package of four bills to help communities deal with the heavy wildfire smoke that has clouded Oregon skies in recent summers.

The Smoke-Ready Communities Act would make grants available for schools, public buildings and vulnerable households to make upgrades to “smoke-proof” their buildings and better filter smoke from indoor air. Other provisions in the bill include requiring farms to provide respiratory protection to farmworkers exposed to hazardous air conditions and authorize the Small Business Administration to provide financial relief to businesses that lose revenue due to wildfire smoke.

“Last August in the Rogue Valley, I looked up at a sun that was neon pink through the thick haze of smoke from wildfires,” Merkley said in a statement about the need for the bill. “Business owners and organizations told me how the smoke caused lost reservations, canceled shows, and even irreparable damage at a furniture store after the fabrics absorbed the smoke smell. Folks told me about respiratory problems even indoors because HVAC systems weren’t equipped to handle the level of pollution they were experiencing.”

SAIF, Oregon’s not-for-profit workers’ compensation insurance company, recommends that businesses have plans in place for evacuations during fires, but also for protecting employees or sending them home when smoke pushes air quality to hazardous levels.

The Department of Environmental Quality now has an OregonAir app for mobile phones to easily check its air quality index, which can also be found online at http://oraqi.deq.state.or.us. When air reaches unhealthy levels, homes and businesses should clean HVAC filters, set air conditioners to recirculate air in buildings and vehicles, keep windows and doors closed, and keep people indoors as much as possible.