Jersey Braces for Another Heatwave

Jersey Braces for Longest Hot Spell of the Year

Jersey could be heading into another heatwave – and possibly its longest stretch of hot weather so far in 2025.

By definition, a heatwave means at least three consecutive days with temperatures above 28°C. Forecasts are predicting highs of 29°C on Friday (15 August), with warm conditions continuing through the weekend and into next week.

The current outlook suggests the hot spell will peak on Tuesday (19 August) at around 29°C before easing to the mid-twenties on Wednesday. For comparison, the average temperature for this time of year is 22°C.

This summer has already brought three official heatwaves to Jersey. The hottest day so far was 30 June, when St Helier hit a sweltering 33.4°C – the highest June temperature on record.

‘Hotter Than It Feels’ Warning

Dave Rigby, senior forecaster at Jersey Met, says a brisk breeze over the weekend could make it feel cooler – around 24°C – but cautions against being deceived by the wind.

“With the wind, you might not feel as hot, but you’ll still get sunburnt just as quickly,” he warned.

Public Health Safety Advice

Public Health Jersey is urging Islanders to take precautions during the hottest part of the day (midday to 6pm) by:

• Staying hydrated and avoiding alcohol or coffee

• Keeping homes cool with curtains drawn and windows open

• Wearing loose, light clothing, a hat, and sunscreen

• Seeking shade and carrying water when outdoors

• Saving strenuous activities for cooler evenings

• Taking cold baths or showers for relief

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Professor Peter Bradley, Jersey’s Director of Public Health, said:

“While warm weather is enjoyed by many, extreme heat can be dangerous – particularly for the most vulnerable. I encourage everyone to take sensible precautions.”

Sea Temperatures Also Unusually Warm

The sea is warmer than usual too, with 19.4°C recorded in St Helier harbour earlier this month – the highest since 2003, when water temperatures briefly topped 20°C.