S.D. Codified Laws § 34-37-19
Any county may, by resolution, regulate or prohibit the use of fireworks outside the boundaries of any municipality in those areas where the fire danger, as determined by use of the South Dakota grassland fire danger index published by the National Weather Service, has reached the extreme category in that county during the period from June twentieth to July second, inclusive, and during the period from December twenty-eighth to January first, inclusive. During any such period, the county's action is suspended if the grassland fire danger index falls below the very high category and again becomes effective if the grassland fire danger index reaches the extreme category. Any violation of a resolution adopted pursuant to this section is a Class 2 misdemeanor.
SDCL 34-37-19