Motala () is a locality and the seat of Motala Municipality, Östergötland County, Sweden with 29,823 inhabitants (41,956 in the entire municipality) in 2010. It is the third largest city of Östergötland, following Linköping and Norrköping. Motala is situated on the eastern shore of Lake Vättern and is regarded as the main centre of both the Göta Canal and the surrounding lake region. History Motala Church dates from the 13th century. For several centuries, Motala remained a small village, mainly regarded as a stopping post on the road to the nearby town of Vadstena, one of the cultural centres of medieval Sweden. However, King Gustav Vasa had a manor house built at Motala and later Queen Kristina had a summer residence built at the spa resort of Medevi, 20 km north of the town. When the Göta Canal was built in the early 19th century, Motala became an important town for the trade on the canal. The builder of the canal, Baltzar von Platen, has his grave beside it. The town received the minor privilege status of köping in 1823, while full city rights were granted as of April 1, 1881. With the Swedish municipal reform of 1971, Motala became the seat of Motala Municipality. Motala Verkstad is an engineering company specialising in bridge and railway construction equipment. In the science fiction novel 20,000 Leagues Under the Sea by Jules Verne, the prow of the submarine Nautilus was built at Motala Verkstad. Later major Swedish industrial manufacturers such as Electrolux and Luxor had their main factories built in the city. In 1963, Tetra Pak installed the first Tetra Brik packaging machine in Motala. Climate Motala has a temperate climate. Lake Vättern provides Motala with slightly cooler summers and milder winters compared to areas of inner Östergötland (± compared to the nearby city of Linköping). The warmest month is July with an average daily mean temperature at , and an average daytime temperature at . The coldest month is February with an average daily mean at , and an average daytime temperature at . Record temperatures between 1961 and 1990, as registered by Motala Kraftverk weather station, reaches from in February 1985 to in August 1975. The most recent data is from Swedish Armed Forces' weather station located approximately 30 km north-east of the city centre. Its inland position renders greater diurnal temperature difference. In addition the geographic location makes seasonal