The Weather Stress Index, or WSI, is a relative measure of the weather conditions, often used as a comfort indicator. The index, a number between 0 and 100, represents the percentage of time in the past with temperatures below the current temperature, for a given location, day and time.
Best Answer:  A free lease means that the horse is leased to someone without any payment to the owner. Now, depending on the contract, the person leasing the horse may have to pay for board, vet, farrier, etc. although some lease agreements may require the owner to pay those bills.
The most common reason a person would lease a horse instead of buy one is that leasing allows you to experience the joys and responsibilities of horse ownership without actually having to buy a horse, and without having to deal with certain liabilities.