It doesn’t matter how well you prepare. When the conditions turn extreme, fire will spread quickly. You can do everything recommended, and you can still end up facing the biggest nightmare of your life. This doesn’t mean it’s not worth taking steps to protect your home. However, you’ll need to understand what extreme fire conditions mean to help you know when it’s time to just get out of dodge. Dropping in Humidity Levels Humidity in the air is a good thing for preventing fires. It’s when the humidity drops that you want to pay close attention. Look out for when the humidity levels drop to below 20%. You’ll also want to keep an eye on moisture content of small fuels.