In terms of foodservice, seasonality has two meanings. The first refers to the time of year a product is in its highest period of abundance, availability, quality, and usually lowest price. Seasonality often refers to produce, but it can also refer to protein types of entre´e dishes. Examples include, but are not limited to finned fish, shell fish, wild game, and turkey.
You can buy many types of fruits and vegetables all year, but that does not mean that they were locally grown. The concept of seasonality suggests that if a restaurant is located in Southern California, for example, and it is the spring season of the year, locally grown strawberries will cost as much as 60 70% less than at other times (when strawberries must be trucked in or shipped from remote areas), and will be more plentiful, colorful, and flavorful.
The second meaning pertains to seasonality of business. Business seasonality exists when guest counts (and correspondingly, revenue) fluctuate according to some seasonal pattern. The ‘season’ may be one of the four seasons of the year, or may be interpreted similarly but applied to days of the week or months of the year.
Rutherford, D. (2001). Hotel Management and Operations. New York (USA): Wiley & Sons.