Jersey weather
Clear sky and 18°C in St Helier right now — high of 28°, low 17°, wind S 2 kt, sea 20°. No rain is expected in the next 24 hours, and nothing significant shows in the 14-day outlook.
14-day outlook
- Today28 JulClear sky28° 17°
- Wed29 JulClear sky28° 18°
- Thu30 JulMainly clear8%23° 18°
- Fri31 JulMainly clear22° 17°
- Sat1 AugClear sky20° 16°
- Sun2 AugOvercast8%24° 16°
- Mon3 AugClear sky20%23° 17°
- Tue4 AugLight drizzle18%22° 18°
- Wed5 AugClear sky11%20° 18°
- Thu6 AugClear sky19%19° 17°
- Fri7 AugPartly cloudy16%21° 17°
- Sat8 AugLight drizzle10%21° 16°
- Sun9 AugLight drizzle10%23° 19°
- Mon10 AugClear sky11%32° 19°
Within 1 °C on 26 of the last 30 days. Every model's day-ahead forecast is checked against what Jersey actually recorded, and the blend weights each model by that recent form — no single model wins every day, and the blend has been beating them all.
Average day-ahead temperature error over the last 30 days, weighted toward recent days — shorter bars are better. Models are scored at Jersey Airport, the island's only station publishing machine-readable observations; the forecast you see is pinned to St Helier. Airport scores rank the models fairly, but don't measure town-level accuracy directly.
When will it rain in Jersey?
No rain is expected in the next 24 hours, and nothing significant shows in the 14-day outlook. The hourly strip above shows the chance of rain for every hour of the next 14 days — pick a day to see its breakdown. Wet hours are highlighted, and when rain is minutes away a nowcast line appears on the card with the expected start time.
What is the sea temperature in Jersey?
The sea around St Helier is about 20°C today — a modelled nearshore value from Open-Meteo's marine model, so treat it as a guide rather than a thermometer reading. Jersey's water is warmest in late summer — typically peaking in September — and coldest in early spring, and with some of the world's largest tidal ranges the shallows over sand can feel noticeably warmer on a rising afternoon tide.
Which weather forecast is most accurate for Jersey?
No single forecast model wins every day, so Jersey Now blends the six high-resolution models that genuinely resolve the island: Météo-France's 1.5 km AROME, the UK Met Office's 2 km UKV, DWD ICON, ECMWF IFS, and the KNMI and DMI Harmonie models. Each model is verified against real Jersey observations, and the blend weights the models by that recent form — over the last 30 days it was within 1 °C of the recorded temperature on 26 days, ahead of every individual model. Sky conditions are decided by consensus between the models and sanity-checked against measured solar radiation so thin high cloud is never reported as an overcast sky, and the whole forecast is pinned to St Helier town rather than the exposed, elevated airport — which keeps temperatures within about a degree of on-island sensors. You can also switch the forecast card to any individual model.
Forecast data is served by Open-Meteo and refreshed every 15 minutes. For official warnings, the source of record is Jersey Met.