Provisional figures for April show that 54.4mm of rainfall was recorded, slightly below the 30-year average for the month. Jersey has now seen lower-than-normal rainfall amounts every month since last May, with the autumn months of September, October and November recording some of the biggest drops when compared to seasonal averages.
Last December, reservoirs dropped so low that Jersey Water turned on the desalination plant for the first time in seven years to help bolster supplies. It was turned off later in the month.
Although Jersey’s reservoirs are now almost full, Islanders are being urged to conserve water to help protect supplies in the event of a dry late spring and summer.
Helier Smith, chief executive of Jersey Water, said: ‘Rainfall levels have been significantly below the five-year average and the previous year. Having said that, our reservoirs are 93% full and that is a good position to be in at this time of the year.
‘The concern for us is over whether the dry weather will continue. The long-range forecasts we get indicate that May and June levels will be in line with average, while July could be drier than normal.
‘Water is a precious resource and it is important that we only use what we need.’
The year, which also saw one of the hottest summers on record, was the 15th driest 12-month period between May and April since records began in Jersey in 1894. However, it is not classed as an unusual event and is not being linked to climate change, which is likely to cause significant fluctuations in rainfall across the seasons.
John Searson, principal meteorologist at Jersey Met, said: ‘It has been a dry 12 months where we have seen 25% less rain than we would normally expect. However, it is not too unusual – we would expect to get periods like this every ten years or so. The danger is that if it continues to be dry going forward then it could begin to be a problem for Jersey Water.’
He added: ‘Climate change is likely to cause drier summers and wetter winters, so a dry 12-month period like this can’t easily be linked to climate change. It was dry last summer, but we have had much drier summers.’
A year’s rainfall
April 2019: Provisional 54.4mm (compared to a 30-year monthly average of 56.2mm)
March 2019: 65.1mm (69.4mm)
February 2019: 63.4mm (70.8mm)
January 2019: 66.6mm (92.4mm)
December 2018: 109.1mm (113.7mm)
November 2018: 77.4mm (106.3mm)
October 2018: 59.8mm (104.7mm)
September 2018: 35.6mm (62.7mm)
August 2018: 43.6mm (51.3mm)
July 2018: 20mm (44.3mm)
June 2018: 41mm (48.2mm)
May 2018: 25.8mm (54.7mm)
