Summary of the weather data for 2021
2021 was the 4th sunniest year since sunshine records began in 1925.
Temperatures
The mean daily air temperature for the year was 12.31°C, just a little below the 1991 to 2020, 30-year average of 12.39°C.
Source: Jersey Met, download the chart data
2021 adds to the Climate Stripes record. It goes on as a light red colour due to the mean temperature for the year being warmer than the 1971 to 2000 base line average temperature.
The record warmest year was 2014 with a mean daily air temperature of 13.34°C.
The highest maximum air temperature recorded during 2021 was 30.1°C on 21 July.
The lowest minimum air temperature recorded during 2021 was -3.0°C on 11 February.
Rainfall
The rainfall total for the year was 905.7mm which is just shy of the 1991 to 2020, 30-year average of 918.2mm.
189 rainfall days were recorded with 0.2mm or more of rainfall. This compares with a 30-year average of 188.2 days per year.
The wettest day of the year was 2 October with 25.4mm of precipitation recorded.
Sunshine
The sunshine total for the year was 2,331.6 hours. 2021 was the 2nd sunniest year since records began in 1894.
The sunniest year on record was 2010 with 2,403.2 hours of sunshine.
Sea temperature
The mean daily sea temperature during 2021 was 12.99°C.
Jersey monthly air temperature and rainfall in
Source: Jersey Met,
download monthly air temperature data from 1894 and
download monthly rainfall data from 1894
Sunrise and sunset times for Jersey in 2021 (GMT)
Source: Jersey Met,
download the sunrise and sunset times since 2015
Long-term weather averages
The long-term annual weather averages for the period 1991 to 2020 were:
- mean daily air temperature of 12.39°C
- 2,092.3 hours of sunshine per year
- 918.2mm of rainfall per year
- mean daily sea temperature of 12.73°C
Temperature, sunshine and rainfall, monthly averages for the period 1991 to 2020
| January | 7.0
| 2.4
| 95.2
|
|---|
| February | 7.0
| 3.6
| 78.4
|
|---|
| March | 8.8
| 5.0
| 67.7
|
|---|
| April | 10.9
| 7.3
| 56.7
|
|---|
| May | 13.7
| 8.3
| 53.6
|
|---|
| June | 16.3
| 8.8
| 50.7
|
|---|
| July | 18.3
| 8.8
| 45.3 |
|---|
| August | 18.4
| 8.0
| 62.0
|
|---|
| September | 16.6
| 6.9
| 59.7
|
|---|
October
| 13.7
| 4.3
| 106.5
|
|---|
November
| 10.2
| 2.9
| 116.4
|
|---|
| Decemeber | 7.7
| 2.3
| 126.0
|
|---|
Source: Jersey Met,
download monthly air temperature data from 1894 and
download monthly rainfall data from 1894
Average annual air temperatures in Jersey since 1900
Source: Jersey Met,
download the chart data
The average (mean) temperature for the 2010s was 12.5°C. This was 1.5°C higher than for the 1900s, which had an average temperature of 11.0°C.
Average annual rainfall in Jersey (millimetres)
Source: Jersey Met,
download the chart data
Further information
Maison St Louis Observatory has recorded meteorological data since 1 January 1894.
The observatory makes an important contribution to studies of climate change and its impact on the Channel Islands.
Records of meteorological elements are also made at several other on-Island and offshore sites.
Data referred to on this page has been recorded at the following sites:
- temperature and rainfall at the Maison St. Louis Observatory
- sunshine at the Fort Regent Signal Station
- sea temperature at St. Helier Harbour
The Jersey Met provide live weather updates, as well as a daily weather summary. Environmental Health provide
live air quality updates. The Jersey Met also provide
weather forecasts for six days into the future.
Monthly weather data from 2009 onwards is available on the
Jersey Met climate page. Information on the climate crisis and the government response to it can be found on the climate emergency page.
gov.je