Sarnia is a city in Southwestern Ontario, Canada (city population 71,419, census area population 88,793, in 2006). It is the largest city on Lake Huron and is located where the three upper Great Lakes empty into the St. Clair River.
The city's natural harbour first attracted the French explorer La Salle, who named the site "The Rapids". The name "Sarnia" was the Latin name for Guernsey in the Channel Islands just off the coast of Normandy, France. The Sarnia port is still an important centre for lake freighters and "salties" carrying cargos of grain and petroleum products. It is the largest community in Lambton County.
The climate of Sarnia is considered a mild climate for Canadian standards. Winters are mild to cold and summers are warm to hot/humid. Lake Huron can create large temperature differences within the city in spring and early summer. Humidex readings can be quite high at times from late May to late September. Thunderstorms can become quite severe from April to September. The area enjoys a longer growing season than cities at similar latitudes, such as London, Ontario, Madison, Wisconsin or Lansing Michigan due to the lake influence. The mild climate of Sarnia is one of the reasons that Sarnia has attracted retirees.
Located on the south shore of Lake Huron Sarnia combines small town friendliness and ease of transportation with big city amenities.