Fig. 3

Prescribed fire weather windows from early spring to late fall by year from 2003 to 2015 within the western Bismarck (top panels) and eastern Grand Forks (bottom panels) fire weather zones that cover North Dakota and Minnesota, USA (Fig. 1). For clarity, the first half of the years are shown in the left panels and the second half of the years are shown in the right panels. Lines are negative exponential smoothed averages of the daily proportion of stations with acceptable conditions over a running four-week period