High temperatures, low humidity, windy conditions contribute to the danger of wildfires. Here is a map from the EPA showing the extent and direction of smoke from wildfires. The haze can make for colorful sunsets and sunrises, and sometimes we can smell smoke.
Here is the link to the interactive map. Use the legend picker in the upper right to turn off the green dots and triangles, etc.:
EPA's Air Now Fire and Smoke Map