A fire tornado formed over a lake amid a series of unusual weather conditions during a wildfire.

The rare sight was captured by ground personnel battling the Downton Lake wildfire in British Columbia, Canada on the night of the August 17 wildfire.

The whirl of flame and smoke appeared as a cold front swept through the Gun Lake area and brought about an unusual combination of factors.

Strong winds caused the fire to grow at a peak intensity. An exceedingly rare reading of 14 per cent of overnight relative humidity was reportedly recorded at about 4:00 am.

Later on, the dew point drastically decreased to -11 degrees Celsius, which helped bring about the striking tornado formation.

Finally, the intricate combination of terrain, downslope winds, and the cold front's influence, resulted in this incredibly rare phenomenon.