Seasons occur in nearly all the Creatures games, excluding the first (although seasons can be seen in Terra Nornia.) There are typically four seasons in a whole year: Spring, Summer, Autumn (Fall) and Winter.
Seasons were first introduced in Creatures 2, with each season lasting a total of two hours. During Summertime, Albia begins to come to life, with caterpillars metamorphosing into butterflies and warm weather. During Winter, however, it can get extremely cold, which can cause the sea to freeze over. Many plants and animals will also become dormant during this season.
Seasons still occur in C3/DS, but more subtly. Although some metarooms can take advantage of the season system, the only effect it has on a standard world is a seasonal gender bias, with more chance of females during spring and more chance of males during autumn, apparently to simulate environmental sex determination. This default can be changed with the No Seasonal Gender Bias .cos file, to make male and female births have the same chance in every season.
The GAME variable engine_LengthOfSeasonInDays sets the season length in days, and by default there are four days in a season - as days are twenty minutes long by default, this makes seasons 80 minutes long.
Some third-party agents, such as the Game Stats agent, Vamp's Calendar, the Dustdevil Grendel Calendar Wheel, the Garden Gnome, and the Ecology Kit, allow the player to see which season it is in the game. Others, such as the 5 in 1 tree and Garden Box patch plants, react to the passing of the seasons. The Seasonal Wolfling Run Tools allow players to set up connectable arrays of agents that activate during certain seasons.
Seasons affect the Creatures Village world on a much larger scale; snow will actually fall and settle on the ground during winter, and different fruit will grow depending on the season. It is worth noting that the playground area will remain broadly the same, regardless of the season, although the desert flower will bloom annually.