"The Sims 2: Seasons is the fifth expansion pack for The Sims 2. It was developed by Maxis, released on March 1, 2007 in North America, and was followed by the European release on March 2, 2007. Aspyr released a Mac OS X port of the game in June 2007.
The Sims 2: Seasons enhances gameplay by adding seasons and weather mechanics. Each season lasts around five sim days and brings with it new challenges and gameplay options. A new type of sim known as a plant-sim is also added. They operate using different mechanics to normal sims. The expansion pack introduced a new neighbourhood called Riverblossom Hills. Like previous games, it has a storyline but no linear gameplay."
Source: Wikipedia, "The_Sims_2:_Seasons," available under the CC-BY-SA License.