Climate averages 1991–2020
Saint Helier weather
in December.
A cool, wet month: the 9th warmest and the wettest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a cool month in Saint Helier: daytime highs average 10.0°C and nights cool to about 7.7°C. By daytime temperature it is the 9th warmest of the 12 months.
Expect about 138 mm of rain on roughly 17 days, which makes December a wet month (the wettest month of the year). Daylight, from sunrise to sunset, lasts about 8 h 17 min on an average December day.
The nearest other city in this atlas is Rennes (124 km away). In December its highs average 8.8°C, 1.2°C cooler than Saint Helier, with 71 mm of rain.
From December to January, average highs fall by 1.0°C to 9.1°C, and monthly rainfall falls from 138 mm to 110 mm.
The annual picture
December in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Saint Helier climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 9.1°C6.8°C | 6.8°C | 110 | 15.8 | 8.79 h |
| February | 8.7°C6.3°C | 6.3°C | 82 | 13.0 | 10.110 h |
| March | 9.7°C7.3°C | 7.3°C | 69 | 12.4 | 11.912 h |
| April | 11.3°C8.6°C | 8.6°C | 57 | 10.5 | 13.714 h |
| May | 13.7°C11.0°C | 11.0°C | 53 | 9.4 | 15.315 h |
| June | 16.1°C13.4°C | 13.4°C | 50 | 8.7 | 16.216 h |
| July | 17.9°C15.4°C | 15.4°C | 48 | 9.1 | 15.816 h |
| August | 18.5°C16.1°C | 16.1°C | 63 | 9.8 | 14.414 h |
| September | 17.5°C15.1°C | 15.1°C | 77 | 11.0 | 12.713 h |
| October | 15.2°C12.9°C | 12.9°C | 122 | 15.5 | 10.811 h |
| November | 12.2°C10.0°C | 10.0°C | 132 | 17.6 | 9.29 h |
| December, selected | 10.0°C7.7°C | 7.7°C | 138 | 16.7 | 8.38 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Rennes in DecemberFrance · 124 kmHigh 8.8°C · Low 3.7°C · 71 mm rain
- Caen in DecemberFrance · 127 kmHigh 8.5°C · Low 4.0°C · 74 mm rain
- Le Havre in DecemberFrance · 164 kmHigh 8.5°C · Low 4.8°C · 121 mm rain
- Poole in DecemberUnited Kingdom · 170 kmHigh 8.9°C · Low 5.4°C · 78 mm rain
- Bournemouth in DecemberUnited Kingdom · 171 kmHigh 8.7°C · Low 5.3°C · 78 mm rain
- Portsmouth in DecemberUnited Kingdom · 193 kmHigh 8.4°C · Low 4.3°C · 92 mm rain
- Brest, France in DecemberFrance · 196 kmHigh 10.4°C · Low 7.4°C · 105 mm rain
- Plymouth in DecemberUnited Kingdom · 197 kmHigh 9.3°C · Low 5.6°C · 109 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Saint Helier) is explained once on the Saint Helier year overview and on the Sources, method and limits page.