Wind, warm weather and tinder-dry conditions have combined to fuel the Decker fire south of Salida, where residents have been evacuated as a precaution.

The fire, sparked by lightning on Sept. 8, has grown to more than 3,700 acres, according to the Decker fire public information office. Massive plumes of dark smoke have filled the sky over the fire area, and fierfighters are battling the blaze around the clock.

“The fire made a big run” on Wednesday in strong winds and single-digit humidity, said Rob Powell, operations section chief of the fire.

On Thursday, winds calmed to about 15 mph with gusts up to 25 mph, but they can “still contribute to an increase in fire behavior,” said Mark Giacoletto, incident commander. Humidity on Thursday remained low, in the 10 to 20 percent range.

Heavy smoke from the #DeckerFire is blocking out the sun along Hwy 50 near Salida. Today, #CDOT also lowered the speed limit between Salida and Wellsville due to all the emergency vehicle traffic. Photo from Doyle Hefner. pic.twitter.com/RyQx40y9k2 — Bart Bedsole KRDO (@BartKRDO) October 3, 2019

Fire crews in the Boot Hill area have been working to slow the fire and protect homes and other structures, fire officials said.

Boot Hill and areas including Methodist Mountain, Pinon Ridge Estates, the Fawn Ridge subdivision and Mountain Vista Village have been evacuated. Residents were instructed to check in at the Chaffee County Fairgrounds for information on the fire. Livestock is being housed at the fairgrounds. Domestic animals are being housed at the Ark Valley Humane Society.

Aircraft are being used to battle the fire. Firefighters are digging break lines with hand crews and bulldozers. The fire was 5 percent contained Thursday, and more than 250 firefighters were working on the blaze. Roads have been closed in the area.

There’s a slight chance of showers between 11 a.m. and 1 p.m. Friday in Salida, with precipitation at about 20 percent, according to the National Weather Service. The high temperature will be about 74 degrees with 15 to 20 mph winds during the afternoon, although winds could gust to 30 mph.

Meanwhile, dry and warm weather along the Front Range is raising concerns about fire danger. On Thursday, fire restrictions were enacted in Jefferson and Douglas counties. In Douglas County, “open burning of any kind” is prohibited. The National Forest Service issued fire restrictions in parts of the state, including a ban on target shooting on Forest Service Lands. Violations of fire restrictions could include a fine of up to $1,000.