Rain is always good news to firefighters battling wild land blazes.
But the threat of summer thunderstorms in the western USA often puts firefighters on the alert. In the dry West, the humidity is often so low that rain falling from thunderstorms evaporates before reaching the ground. Even though the rain doesn't make it to the ground, flashes of lightning streak from the clouds to the ground. This lightning can start fires in dry woods with no rain to extinguish or slow the blazes. Lightning accounts for a large number of the forest fires in the West.