clinging to the East Anglian coast, February 2008; Norwich is denoted by the yellow dot.
Norwich, like the rest of the British Isles, has a temperate maritime climate. It does not suffer extreme temperatures, and benefits from rainfall fairly evenly spread throughout the year. Coltishall, about 18 kilometres (11 mi) to the northeast, was the nearest official met-office weather station for which records are available, although it ceased reporting in early 2006 – now Norwich airport provides readings. Norwich's position in East Anglia, jutting out into the North Sea can produce weather conditions that have less effect on other parts of the country, such as snow or sleet showers during the winter months on a northerly or easterly wind, or sea fog/haar during the summer half of the year. An example of Norwich being afflicted by sea fog is shown in the adjacent image.
The highest temperature recorded at Coltishall was 33.1 °C (91.6 °F) during June 1976. However, go back further to 1932, and Norwich's absolute record high stands at 35.6 °C (96.1 °F). Typically the warmest day of the year should reach 28.8 °C (83.8 °F) and 9.9 days should register a temperature of 25.1 °C (77.2 °F) or higher.
The lowest temperature recorded at Coltishall was −15.3 °C (4.5 °F) during January 1979. In a typical year however, the coldest night should only fall to −7.5 °C (18.5 °F). On average 39.4 air frosts will be recorded during the course of the year. More recently, the temperature at Norwich airport fell to −14.4 °C (6.1 °F) on 18 December 2010 with unofficial weather stations reporting localised readings of −17 and −18 °C (1 and 0 °F).
The nearest sunshine monitoring weather station for which records are available is Morley agricultural research centre, about 11 miles (18 km) southwest of Norwich city centre. For the 1961–90 period, it averaged 1558 hours of sunshine a year, a relatively high total for an inland part of the British Isles outside of southern England. In reality, given Norwich's position nearer to the coast and as such suffering from less convective cloud development during summer, true totals may even be slightly higher than this.
Rainfall, at around 650 millimetres (25 inches), is low, although as much as 100 millimetres (4 inches) higher than other, more sheltered parts of East Anglia, as Norwich is more prone to showers originating from the North Sea.