Idling with Air Con Could Land You a Fine
As the UK swelters under a record-breaking heatwave, with temperatures hitting 36.1°C in Hampshire, many drivers may be tempted to sit in their cars with the engine running to keep the air conditioning on. However, motoring experts warn this could be an expensive mistake.
The RAC cautions that drivers who remain stationary with the engine idling risk a fine for breaking vehicle emissions laws. The standard penalty for engine idling across the UK is a fixed penalty notice ranging from £40 to £80, often halved if paid promptly. Some councils, such as Islington and Westminster in London, have imposed fines of up to £110.
Highway Code Rule 123
Rule 123 of the Highway Code states: "You must not leave a parked vehicle unattended with the engine running or leave a vehicle engine running unnecessarily while that vehicle is stationary on a public road." It advises that if the vehicle is stationary for more than a couple of minutes, drivers should apply the parking brake and switch off the engine to reduce emissions and noise pollution. This does not apply when stuck in traffic queues.
Wales Introduces Higher Fines
In Wales, the Welsh Government is upgrading the current £20 fixed penalty fine to a range of £75-£150 from 30 September 2026. It explicitly states that "unacceptable reasons for idling" include "operating heating/cooling systems for comfort." The government cites health risks, noting that idling "creates air and noise pollution which is harmful to public health" and "contributes to a range of problems including heart and lung diseases." Children, young people, and those with existing health conditions are particularly vulnerable.
RAC Advice and Leniency
RAC senior policy officer Rod Dennis said: "Air conditioning is a game-changer in modern vehicles, making otherwise uncomfortable journeys by road a genuinely pleasant experience. We even advise those driving vehicles without air-con to consider delaying any non-essential trips this week until the heatwave passes. But while we’re all desperate to stay cool, just sitting in the car with the engine and air conditioning running and going nowhere isn’t advisable. Due to the air pollution this causes, you risk a fine from a police or civil enforcement officer."
However, given the extreme heat conditions, police or enforcement officers may apply some leniency. Nonetheless, drivers are advised to switch off the engine when stationary to avoid fines and reduce pollution.
