Which condition can accelerate the spread of a fire in an outdoor environment?

Strong winds can significantly accelerate the spread of a fire in an outdoor environment due to their ability to carry flames and embers across distances. Wind increases the availability of oxygen to the fire, which is essential for combustion, and can push the fire into unburned areas, rapidly expanding its reach. The force of the wind can also cause flames to leap or spread laterally, affecting a much larger area and making it more difficult for firefighters to contain the fire. This is particularly concerning in grassland or forested areas where vegetation is present.

In contrast, high humidity levels and low ambient temperatures generally do not promote fire spread; high humidity can help to dampen materials, making them less ignitable. Similarly, calm weather conditions do not facilitate the movement of flames or embers and can result in slower fire progression compared to windy conditions.