The monthly 24-hour average temperature ranges from 5.5 °C (41.9 °F) in January to 29.5 °C (85.1 °F) in July, while the annual mean is 18.00 °C (64.4 °F). Annual precipitation stands at around 1,610 mm (63 in); with monthly percent possible sunshine ranging from 23 percent in March to 60 percent in August, the city receives 1,832 hours of sunshine annually in average. Extremes since 1951 have ranged from −9.7 °C (15 °F) on 29 December 1991 to 40.6 °C (105 °F) on 23 July 1961.[16]