The day-to-day weather has very little impact on the volume of visits to Jersey, but can play a major role in influencing the types of activities that visitors who are here do, and thereby, the amount of money that they spend. Some attractions and activity providers thrive only when the sun shines, others see higher patronage on rainy days.
The following tables show the monthly profile of temperatures, rainfall and sunshine over the past three years, the annual change, and finally the variance to the thirty-year average. When looking at the monthly figures warmer temperatures, drier weather and higher sunshine hours are shaded green, and when looking at comparisons a warmer, drier and sunnier relative outcome is shaded green.
The average temperature in December was 8.2oC, the same as the year before and 0.8oC up on the thirty-year average. Rainfall totalled 182mm for the month, which is a near nine-fold increase compared with the exceptionally dry December of 2016, and makes the past December Jersey’s wettest month since January 2016. amount of rainfall in December 2017 was roughly 50% more than the seasonal norm.
Looking at the number of hours of sunshine we find that the total of 56.6 hours, some 42 hours down on December 2016 and nearly 11 hours fewer than one might expect based on the thirty-year average.
In summary, the December weather was a lot wetter than is the norm as well as being less sunny, but at least temperatures were slightly above average.
Averages can be misleading – you can have many values that are a bit below normal being offset by a single value that is significantly above normal. In meteorological terms for example you could have a month during which 28 days see not a drop of rain, but three days of torrential downpours. Statistically this might lead to an ‘average’ amount of rainfall for the month, but most visitors would not have experienced ‘average’ weather.
Looking at December there were eight days when no sunshine was recorded with a further thirteen days when the sun shone for an hour or less.
The lowest minimum temperature was recorded on 12 December at 1oC, while the penultimate day of the month saw the warmest temperature at 13oC.
There were just five days with no recorded rainfall and seven days with only trace amounts. The wettest days of the month were 9 and 10 December with 27mm and 31mm respectively.