Last weekend saw a 65% spike in gas use as Brits felt the chill after a baking hot summer, according to npower.
The surge in the number of people turning on their heating on Saturday 14 September, compared to the previous weekend, occurred despite the temperature dropping by just 0.25°C compared to the same time last year.
Gas usage across September is 15% higher than it was this time last year, suggesting many of us are feeling chillier this year than we did in September 2012.
Npower puts the anomaly down to families experiencing a "faux winter", where it feels colder than it really is because we've had such a hot summer.
But while the heating may have been on for the past few weeks, npower says we'll be turning it back off in a few days when temperatures are set to increase – maybe to 20°C by Saturday, according to BBC Weather – and demand drops again.
The last weekend of October is forecast to mark the real onset of winter, when boiler timers will spring back into action across the UK.
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Sunday 26 October will be the tipping point, an nPower survey predicts, as that's the date on which 60% of households expect to opt for an evening in front of the TV and turn the heating on.
Further research from the energy provider found that from the beginning to the middle of September, 45% of people turned on their central heating for the first time since the summer. A further 23% plan to turn it on during the next two weeks and 18% will hold out until November or later.
If you're worried about your energy bills this winter, here are 10 top tips to help you keep them under control:
1. Turn the thermostat down
2. Insulate properly
3. Don't lose heat through your loft
4. Get rid of draughts
5. Improve your radiators
6. Look after your boiler
7. Monitor your energy use
8. Buy efficient appliances
9. Don't waste electricity
10. Check for benefit entitlements such as the cold weather and winter fuel payments