Objectives To comprehensively explore the distribution law and change trend of forest fire occurrence frequency and fire risk period in The Greater Hinggan Mountains, and to investigate the temporal and spatial characteristics and dynamic change law of forest fire occurrence. The findings of this study will provide a theoretical basis for forest fire prevention and control deployment in the Greater Hinggan Mountains.

Methods Based on the recorded fire point data from 1988 to 2020 in the Greater Hinggan Mountains, the interannual and temporal dynamic characteristics, seasonal dynamic characteristics, fire risk deviation, and spatial dynamic characteristics of forest fires in the region were analyzed utilizing data statistics and Mann-Kendall trend test.

Results (1) The number and area of forest fires in the Greater Hinggan Mountains during the period from 1988 to 2020 exhibited an increasing trend. During daylight hours, the occurrence of forest fires was prevalent, with the greatest extent of combustion occurring between 7:00 and 8:00, 10:00 and 11:00, and 13:00 and 14:00. (2) The majority of man-made fires occurred in spring and autumn, while lightning-induced fires were more prevalent during the summer. In spring, both the number of fires and the burned area exhibited a trend of initial decline, followed by an increase, and then a decline once more. The number of fires in summer demonstrated a downward trajectory, followed by a resurgence. Conversely, the burned area exhibited a declining pattern. In autumn, the number of fires and the burned area showed no obvious trend and demonstrated a fluctuating pattern. The number of days in the annual fire danger period has decreased from 172 days in the period 1988—1994 to 117 days in the period 2011—2020. Furthermore, the fire danger period showed a trend of migration and concentration to summer. (3) The geographical distribution of forest fires was scattered, and no obvious rule could be discerned. However, in recent years, the number and area of fires in Tahe, Huzhong, and Songling have increased, while the other southern and northern regions have decreased.

Conclusions Forest fires in the Greater Khingan Mountains had clear temporal and spatial distribution characteristics, with the fire risk period concentrated in summer. Therefore, the fire prevention period should be properly adjusted promptly and fire resources should be allocated reasonably.