Spokane Valley Fire Marshal Greg Rogers said it doesn’t make much difference whether the lot is mowed or not when it comes to how fast a fire spreads. “An overgrown lot may produce bigger flames, but the wind determines how fast the fire spreads,” Rogers said. Rogers is much more worried about potential ignition sources than the size of the weeds. And the most common igniters aren’t surprising: children with matches and lighters, cigarette butts thrown out of car windows or off hiking trails and cigarettes put out in dry potting soil.Though he didn't say it (or at least wasn't quoted as saying it) this obviously applies to urban situations, not the big forest fires. Most experts will emphasize the defensible space vastly more than the igniters. With good reason, I guess; the difference is real and dramatic out in the forest. You don't want to confuse the public. Still, this don't confuse approach has led to a lot of bad advice in other situations. People who deal with prisons and insane asylums know with certainty that tobacco controls impulses and keeps inmates calm. Despite this, they go along with prohibitions of smoking based on "second-hand smoke" crap, causing unneeded problems inside the walls. Diet experts have known for a long time that animal fats and cholesterol were not the main problem, but they went along with the nonsense, causing a lot of unneeded deaths. Looking at the fire starts in recent days, temperature is the ONLY relevant variable within Spokane. Wind doesn't count. During several days with T>90 and ZERO wind, we had a barrage of little brush fires. Today, 72 degrees with wind in the 20s, absolutely NO new fires in town. Using the Rogers assumption: Is this difference a temperature gradient on combustible materials? Does it take 90 instead of 70 to get a fire going? Or is it a gradient on combustible humans? It's unquestionably true that assholes like it hot. Assholes go out and break things when T>90. Assholes do NOT like cool or rainy or weird weather, and today's dense smoke is definitely weird.