A downside of nice Seattle weather: spontaneous combustion

The warm weather made a welcome comeback in Seattle, but it's also caused a few problems.

Three fires in the city in May were caused by spontaneous combustion, which happens when something heats-up internally and bursts into flames.

It happened most recently Saturday at a house in Fremont, when organic material in a flower pot spontaneously caught on fire.

Seattle Fire Department’s Kristin Tinsley described the other two.

“We had the Salmon Bay Marina boathouse fire and Maple Leaf residential fire,” Tinsley said. “And both of those were caused by spontaneous combustion from oil-staining rags.”

The National Fire Protection Association estimated that oily rags account for more than a third of spontaneous combustion fires.

Tinsley said warm and dry weather can increase the risk of these kinds of fires, especially with things that burn easily like bark, hay and other agricultural products. She said there are some simple steps you can take to prevent them, starting with those rags:

"We recommend that people dispose of oily rags in metal containers with a tight fitting lid, removing long grass weeds or anything that can burn from around your home,” she said. “And then, checking for tree branches that touch your home or hang near the roof.”