The city has an oceanic climate. . Cambridge currently has two official weather observing stations, the National Institute of Agricultural Botany (NIAB), about 1 mile (2 km) north of the city boundary near Histon, and the Cambridge University Botanic Garden, about 1 mile south of the city centre. In addition, the Digital Technology Group of the University’s Department of Computer Science and Technology maintains a weather station on the West Cambridge site, displaying current weather conditions online via web browsers or an app, and also an archive dating back to 1995.
The city, like most of the UK, has a maritime climate highly influenced by the Gulf Stream. Located in the driest region of Britain, Cambridge’s rainfall averages around 570 mm (22.44 in) per year, around half the national average, The driest recent year was in 2011 with 380.4 mm (14.98 in) of rain at the Botanic Garden and 347.2 mm (13.67 in) at the NIAB site. This is just below the semi-arid precipitation threshold for the area, which is 350mm of annual precipitation. Conversely, 2012 was the wettest year on record, with 812.7 mm (32.00 in) reported. Snowfall accumulations are usually small, in part because of Cambridge’s low elevation, and low precipitation tendency during transitional snow events.
Owing to its low lying, inland, and easterly position within the British Isles, summer temperatures tend to be somewhat higher than areas further west, and often rival or even exceed those recorded in the London area. Cambridge also often records the annual highest national temperature in any given year – 30.2 °C (86.4 °F) in July 2008 at NIAB and 30.1 °C (86.2 °F) in August 2007 at the Botanic Garden are two recent examples. Other years include 1876, 1887, 1888, 1892, 1897, 1899 and 1900. The absolute maximum stands at 38.7 °C (101.7 °F) recorded on 25 July 2019 at Cambridge University Botanic Garden, which is also the national all time temperature record. Typically the temperature will reach 25.1 °C (77.2 °F) or higher on over 25 days of the year over the 1981–2010 period, with the annual warmest day averaging 31.5 °C (88.7 °F) over the same period.
The absolute minimum temperature recorded at the Botanic Garden site was −17.2 °C (1.0 °F), recorded in February 1947, although a minimum of −17.8 °C (0.0 °F) was recorded at the now defunct observatory site in December 1879. More recently the temperature fell to −15.3 °C (4.5 °F) on 11 February 2012, −12.2 °C (10.0 °F) on 22 January 2013 and −10.9 °C (12.4 °F) on 20 December 2010. The average frequency of air frosts ranges from 42.8 days at the NIAB site, to 48.3 days at the Botanic Garden per year over the 1981–2010 period. Typically the coldest night of the year at the Botanic Garden will fall to −8.0 °C (17.6 °F). Such minimum temperatures and frost averages are typical for inland areas across much of southern and central England.
Sunshine averages around 1,500 hours a year or around 35% of possible, a level typical of most locations in inland central England.