Does WARM WEATHER START FIRES?
No, but pushing a burning car into a gulley does.
Technically, warm weather does start a lot of the fires out west.
Heat lightning strikes happen all over the western US. The difference is when lightning strikes the timberland of a private landowner they send up their helicopter and spot he fires. They they drop off their own private crews to put the fires out before they get too big.
If the same lightning strikes BLM or US Forest Service land they have a meeting to decide IF they should put the fire out. Many times this allows a small fire to grow into hundreds of thousands of acres before they try to put it out.
They other major difference is that the private timber companies routinely go out a thin the underbrush and dead/dying timber on the properties. They do this because dead wood is more likely to start on fire than green standing timber.
It all comes down to the fact that the timber company has a vested interest in not seeing their assets(the trees) burn down. It cost them money. With government lands it is other peoples money. Who cares. Until it burns YOUR house down.