WITH an average temperature 1.5°C above the long-term average, 2025 was Jersey’s fourth-hottest summer on record.
Figures released by Jersey Met showed the average temperature across June, July and August was 19.2°C, just below the record summers of 1976 and 2022 but well above the 30-year average mark, measured between 1991 and 2020.
Warm weather was a feature of the early stages of meteorological summer, with the hottest June on record being recorded this year.
This year’s summer was also sunnier than normal, with a figure of 846 hours being around 60 higher than the long-term average, but well short of the 999 hours recorded in 1976.
After rainfall levels that were around average in June and July, August was significantly drier than usual, with 28.3mm being less than half of the 30-year average mark. This left an overall summer rainfall figure of 127.5mm, around 30mm below the long-term average.
After the hottest day of the month on Bank Holiday Monday, when a temperature of 29.5°C was recorded, more than 80% of the month’s rainfall was recorded after 27 August, while the start of September has also been wet, with more than 20mm falling across the first three days.
Jersey Met has also been recording sea temperatures since 1960, and said 2025 had seen the second-highest average figure for the summer period.
Summer stats
Hottest summers (average temperature across June, July and August)
- 2022 – 19.6°C
- 1976 – 19.5°C
- 2003 – 19.3°C
- 2025 – 19.2°C
2025 extremes
- Hottest day – 33.4°C (30 June)
- Wettest day – 13.4mm (6 June)
