Extreme heat hits EV driving range harder than expected, according to new findings.

The new real-world study by What Car? finds that hot weather affects EVs more severely than winter conditions, in some cases reducing range by nearly half.

According to the research, the EV range fell short of the advertised figures by up to 44% during driving temperatures between 32 °C and 44°C (90°F and 112°F).

In contrast, a similar test conducted in milder 10–11°C conditions revealed a smaller, yet still significant shortfall of 30%.

On test

Researchers drove three EV models on a route from Seville to Córdoba, Spain:

  • Citroën e-C3 Max: achieved 142 miles, 29% below its official 199-mile range

  • Kia EV3 Long Range GT-Line S: managed 246 miles, 32% down from 362 miles

  • Tesla Model 3 Long Range RWD: covered 244 miles, a steep 44% below its 436-mile WLTP figure 

When measuring efficiency (mi/kWh), the results reversed order: the e-C3 scored 2.7 mi/kWh, the EV3 2.9 mi/kWh, and the Model 3 3.0 mi/kWh.

What Car?’s reviews editor, Will Nightingale, summarised: “Our extreme temperature test shows that range and efficiency plummet in very hot conditions. The three EVs fell an average of 35% short of their official figures […] more than double the discrepancy seen in the 2024 What Car? summer range test.”

Real-world data from Recurrent Auto supports these findings, showing minimal range loss of ~5% at 32°C, rising to 17–18% in extreme heat (above 37°C).

The American Automobile Association (AAA) similarly found that 95°F (35°C) heat reduced EV range by about 17%, compared to optimal ambient conditions.

Speed leads

Data from Geotab, based on millions of real-world EV trips, reveals that speed can impact range even more than temperature.

For example, a 65 kWh electric van’s range drops from 143 miles at 50 mph to just 88 miles at 80 mph, a 39% reduction, even in 30°C heat.

Geotab’s senior sustainability manager, Charlotte Argue, notes: “Drivers tend to worry about using the aircon in hot weather, but our data shows that your right foot can make the biggest difference, particularly at high speeds. Just slowing down by 10 or 15 mph can extend your range by 20-30%.” 

Hit tips 

To help motorists manage EV range more effectively in summer, experts recommend:

  • Precondition your EV while still plugged in — cool the battery and cabin using mains power instead of battery charge.

  • Reduce driving speed — especially on motorways, where aerodynamic drag is significant.

  • Use air conditioning smartly — set to recirculate and prioritise seat ventilation to limit battery drain. 

While extreme heat may not be common in the UK, yet, its impact on EV range is undeniable and projected to grow with climate change.

Motorists should be prepared: real-world conditions differ significantly from official WLTP figures.

Whether it’s extremely hot or cold weather, simple strategies like pre-cooling or pre-warming, moderating speed, and smart climate control use can help mitigate range loss.