There is no definitive answer to this question as the best month to buy a mattress depends on individual circumstances and needs. However, there are certain times of year when mattresses generally go on sale, so these may be worth considering if you are looking for a good deal. For example, many retailers offer discounts during Memorial Day and Labor Day weekend sales. Additionally, some stores run promotions around the end of winter in order to clear out inventory before the spring rush. Ultimately, it is important to do your research and compare prices before making a purchase, regardless of the time of year.