ström river flows through the city has a parade annexed. In connection to the latter is the industrial landscape where the old textile industries once were situated. In the summer, there is a cactus plantation in Carl Johans Park. 25,000 cacti planted there every summer. Kolmårdens Djurpark is a zoo located north of Norrköping. In connection to the large outdoor zoo, there is also Tropicariet, an aquarium, where for example snakes, crocodiles and sharks can be seen. The archipelagos away from Norrköping are called St Anna and Gryt. Other locations of note includes a campus of Linköping University, its own symphonic orchestra, an airport called Kungsängen with 170,000 traveling (2006), a high-tech industry park called Norrköping Science Park, and Petroglyphs from the Nordic Bronze Age. Climate Norrköping had a humid continental climate (Dfb) for the reference period of 1961–1990, but it was borderline four-season oceanic (Cfb) during that period and has since more resembled the latter, with somewhat warmer temperatures year-round. In spite of it being located near the Baltic Sea, Norrköping has a relatively dry climate with precipitation levels averaging between 1961 and 1990. That would in turn be very low for a marine climate, but some way above more arid climates. The humidity for most of the year combined with there being no pronounced dry season keeps the surroundings green in spite of the rain shadow effect. Winter precipitation is quite low, but often falls as snow. On August 26, 2016, Norrköping set a nationwide record for the hottest temperature in the latter parts of August with during a sudden and brief burst of extreme heat. Demography Notable natives Herman Theodor Lundgren – entrepreneur Thecla Åhlander – stage and film actress Hannes Alfvén – physicist, Nobel Prize winner Joannes Olaus Alnander – 18th Century author Malin Baryard – Olympic equestrian Amy Diamond – singer Eva Gothlin – historian Elin Grindemyr – model Eldkvarn – music group Peter Harryson – actor, entertainer Markus Krunegård – solo singer and member of Laakso Charlotta Löfgren – poet Mats Löfving – police chief Laakso – music group Marduk – music group Moa Martinson – author Ture Nerman – poet and socialist politician Betty Olsson - suffragist and peace activist Magnus Pääjärvi-Svensson – NHL hockey player Slagsmålsklubben – electronic popgroup Jeffery Taylor – basketball player (Real Madrid Baloncesto) Michael B. Tretow – producer and audio engineer Pernilla Wiberg – alpine skier, double Olympic