Was at a friends house in rural Ohio one day and a barn about 1/4 mi away caught fire. We noticed the smoke first. Then as we watched the entire structure was engulfed in flames. Old weathered barn. Farmer stored hay inside. In 15 minutes it was a pile of ash. Fire dept showed up and sprayed the embers. Absolutely shocking how fast the entire structure went up.
Here is a really good article concerning Barn Fires...Jan,Feb,Mar three worse months. 700pm to 0700am worse times. Heaters, elec equip largest cause.
Barn Fire Safety - Fire Safety In Barns