Weather Future

What Does Weather Future Mean?
A type of weather derivative that obligates the buyer to purchase the value of the underlying weather index - measured in heating degree days (HDD) or cooling degree days (CDD) - at a future date. The settlement price of the underlying weather index is equal to the value of the relevant month's HDD/CDD multiplied by $20. Weather futures enable businesses to protect themselves against losses caused by unexpected shifts in weather conditions.

Investopedia explains Weather Future
The popularity of weather futures is growing rapidly and becoming a more common method for energy companies to hedge against a change in demand due to changes in temperature. For example, if the month of October is warmer than expected, customers will not use as much heat. This will cause a loss for the energy company. If, however, the energy company has sold a weather future for the month of October, the energy company will receive (because it's obliged to sell) the value of October's HDD, providing compensation for its losses.