Saint Helier weather in October
In October, Saint Helier has daytime highs averaging 15 °C, nights around 13 °C, with 15 wet days, and a sea temperature of 16 °C. Figures are 1991–2020 climate normals.
- 15.2°C Average high
- 12.8°C Average low
- 15days Wet days
- 119mm Rainfall
- 15.9°C Sea temperature
- 11h Daylight
Daily temperatures through October
How October develops
Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.
| Days | Avg high | Avg low | Chance of rain |
|---|---|---|---|
| 1–10 October | 16.1 °C | 13.8 °C | 50 % |
| 11–20 October | 15.2 °C | 12.8 °C | 45 % |
| 21–31 October | 14.5 °C | 12.1 °C | 51 % |
- Average highs fall from 16.1 °C early in October to 14.5 °C by the end of it.
- Rain is most likely over days 21–31 of October (51 % of days) and least likely over days 11–20 (45 %).
What to expect
| Measure | Typical October | Share of the month |
|---|---|---|
| Days above 25 °C | 0 of 31 | 0 % |
| Days above 30 °C | 0 of 31 | 0 % |
| Days below 0 °C | 0 of 31 | 0 % |
| Days with more than 1 mm rain | 15 of 31 | 48 % |
Conditions in October
| Measure | Average |
|---|---|
| Mean temperature | 14 °C |
| Record high (1991–2020) | 22 °C |
| Record low (1991–2020) | 5.2 °C |
| Relative humidity | 77 % |
| Wind speed | 35 km/h |
| Cloud cover | 68 % |
October compared with the months around it
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| August | 18.6 °C | 65 mm | 57 % |
| September | 17.6 °C | 74 mm | 59 % |
| October | 15.2 °C | 119 mm | 68 % |
| November | 12.2 °C | 131 mm | 73 % |
| December | 10.0 °C | 134 mm | 73 % |
See all twelve months for Saint Helier
- October is the 5th warmest month here.
- It is the 10th driest month of the year.
- It ranks 8th for least cloud cover.
- Days last about 11 hours from sunrise to sunset.
- It rains on 15 of 31 days — 48 % of the month.
- Nights are about 2.4 °C cooler than the middle of the day.
- The hottest October day on record since 1991 reached 22 °C, 7.2 °C above the usual daytime high.
- Beach score: 11 / 100 — see how this is calculated.
QuestionsOctober in Saint Helier, answered
How warm is Saint Helier in October?
Daily highs average 15 °C and nights fall to about 13 °C, a spread of 2.4 °C between afternoon and dawn. That makes October the 5th warmest month of the year here.
Does it rain much in Saint Helier in October?
October averages 119 mm of rain, spread over about 15 of the 31 days — 48 % of the month. Cloud cover averages 68 % of the sky.
Is the sea warm enough to swim in October?
The sea averages 16 °C off Saint Helier in October. Most people find water below 20 °C bracing and above 25 °C comfortable for a long swim; this figure is a monthly surface average, so a sheltered bay on a still afternoon can be warmer.
How long are the days in October?
Saint Helier averages 11 hours between sunrise and sunset in October. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.