With all the news of fires in the West, especially the Carr Fire in northern California, I thought I'd look at the statistics. This year-to-date is a little worse than average (3.7 M acres) for the last 11 years. The trend line is positive, but I'm not going to draw it because with only 11 years of data it's not very statistically significant.
However, the annual data go back much further:
The trend is +65,000 acres/yr, about 1.5% per year.