It will depend on the wind speed and the fuel in the area of the home. The wind and embers will come first, followed by the fire front which can create intense heat, smoke, and noise. The darkness and roar of the fire can be great and extremely scary. Common descriptions are of a freight train coming straight for the house, and a sky so dark it is like midnight. The heat and smoke can be uncomfortable if one is inside the house as the fire front passes. Remember that temperatures outside the home can be as much as four times warmer than inside. In most fires, this should be less than 10 minutes. This will be followed by an extended (many hours) period after the fire front passes where embers continue falling and burned wood smolders.