OKC-approved burn days require the wind speed to be below 15 mph and the Burn Index (BI) to be below 30 for the entirety of the day across four counties touching OKC. This chart displays the forecasted wind speed and burn index for any given hour in the OKC area, pulled from Mesonet's OKC East, Norman, Yukon, and Shawnee stations. The maximum from these stations is chosen and the resultant plot is used to determine whether the conditions will be at or below the threshold of 15 mph for wind speed and 30 for the burn index over the entire day and over all those counties simultaneously. Qualifying burn windows (3 hours after sunrise to 3 hours before sunset) are shaded green; gray bands mark night.