WATCH: How far can electric cars go in extreme heat?

It’s a well-known fact that electric cars don’t like cold weather. In short, you’ll enjoy a longer range and better efficiency on a warm summer’s day than in the depths of winter. But what about when it’s hot? Really hot? While extreme heat is still (thankfully) quite rare in the UK, the planet is undoubtedly heating up. We’ve already seen temperatures of more than 40deg C in the south and multiple heatwaves have swept the country this summer.

The situation is even more extreme in southern Europe, where temperatures have hit record highs in recent years and wildfires have ravaged communities like never before. And that begs the question: what effect will rising temperatures have on the electric vehicles (EVs) most of us will be driving around in soon, if we aren’t already?

Video: How far can electric cars really go in extreme heat?

To find out, we decided to head to the hottest part of Europe with three popular EVs. The cheapest is the Citroën e-C3 Max, which costs £22,295 (after the £1500 Electric Car Grant for EVs costing less than £37,000 has been factored in) and has an official range of 199 miles.

Next up is the Kia EV3, our reigning Small Electric SUV of the Year as seen in our 2025 What Car? Car of the Year Awards. It’s appearing here in Long Range GT-Line S form with a 78kWh usable capacity battery. Its official range is 362 miles and it wears a list price of £43,005.

Our third and final contender is the Tesla Model 3, featuring here in its longest-range form. That means a 75kWh battery, a single motor driving the rear wheels and one of the longest official ranges of any EV on sale: a whopping 436 miles. If you want one of these, you’ll be spending £44,990.

The preparation 

Our original plan was to set the climate control in our cars to 21deg C. However, during preparation the day before testing, we found that maintaining said temperature in both the EV3 and Model 3 required dialling in a slightly lower temperature of 20.5deg. The e-C3’s thermostat was spot on when we verified it with a digital thermometer.

After the three cars had stood overnight in the same ambient air temperature, our first job was to check that their tyre pressures were adjusted to the manufacturers’ recommendations. To ensure consistency, we did this in the shade before the blistering sun had a chance to heat up any of the tyres.

We then reset the trip computers and left the EV3 in its default Normal driving mode, with the adjustable regenerative braking system (which harvests energy to help eke out range) set to level one. We switched the Model 3’s acceleration level to Chill, which also reduces the aggressiveness of its always-on regenerative braking, and decided to use the regular Drive setting for the e-C3, rather than switching off the regen by using Coast mode.

The test 

Our starting point was a bank of Tesla Superchargers on the outskirts of Seville, which (mercifully) had canopies over them to shield us from the brutal Andalusian sun. It was only 10am, but the temperature was already 32deg and rising rapidly as the batteries in our EVs ticked up from around 90% to fully charged.

While Seville holds the unofficial temperature record for Europe (a sizzling 51deg back in 1876), this is generally considered unreliable, because it was measured using old-fashioned instruments. The city’s official record of 46.6deg is hardly chilly, but our first stop was a place that had reached even hotter temperatures.

Córdoba hit 46.9deg in August 2021 – and getting there involved roughly 90 miles of motorway driving through ‘the frying pan of Andalusia’. By the time we arrived at 12.30pm, the thermometer was showing 37deg, and the wall of heat that hit us when we stepped out of our air-conditioned interiors to pick up coffee (and more water) wasn’t much different from walking into a sauna.

With plenty of charge left in all three (or so we thought), we headed for our next waypoint: Montoro. This holds the record for the highest monthly average maximum temperature ever recorded in Europe (41.4deg in July 2015) and was only 30 miles down the road. However, it soon became clear that the e-C3 would struggle to make that distance. To make matters worse, we were now in a part of Spain with relatively few public charging points. With no coverage from ZapMap (our charging point app of choice back in the UK), we were relying on an unfamiliar phone app called Electromaps.

Fortunately, as the e-C3’s battery level hit an indicated 10%, the app notified us of a bank of 11 ultra-rapid chargers just a few miles down the road. We arrived with less than 10% remaining – closer than you’d probably push it if you were going on holiday, but not tight enough to have us truly panicking. That was until we realised that none of the chargers were switched on. Talking to an employee using a combination of our terrible Spanish and his slightly better English, we learnt that the stalls had been installed roughly a year ago but had never actually been connected.

We were faced with a dilemma: call out a recovery truck or risk getting to the next charging point about six miles away. Burnt by our experience with Electromaps, we decided to send the EV3 and Model 3 on ahead to check whether that site (a) existed and (b) was working. The good news was that the answer to both was ‘yes’. The bad news was that there was only one stall, it had a maximum output of 50kW and someone was already using it.

Still, we decided it was worth the risk and the e-C3 just made it there, with 3% remaining. The inconvenience of a 45-minute wait for the charging point to be vacated was frustrating, but at least there was a shop around the corner that sold ice creams. Crisis averted.

While the e-C3 was replenishing its battery, our other EVs left Montoro and headed for the spot that recorded Spain’s highest ever official temperature. La Rambla, a municipality in the province of Córdoba, reached a melting 47.6deg in August 2021, and wasn’t much cooler (at 44deg) as we negotiated the narrow cobbled streets before rejoining the motorway in the direction of Seville.

It was already clear we weren’t going to get anywhere near the ranges our EVs can officially manage – and while it’s true that much of our trip had been on motorways with a speed limit of 100km/h or 120km/h (62-75mph), this meant it was fairly representative of a long motorway journey in the UK.

Surprisingly, given that it has the longest official range of the trio, the Model 3 was next to hit a 10% state of charge. However, it was a matter of seconds before the EV3 ticked onto the same percentage, so we decided to take both cars to another Supercharger location in a town called Aquadulce, which, as luck would have it, was only about three miles farther down the road.

We rolled into the car park at 7.20pm with the Model 3 showing 9% and the EV3’s battery still on 10%. It was still a balmy 40deg C, but at least the sun intensity had dropped enough so that we could stand outside and talk through our results without risking being air fried.

The results 

It was hardly surprising that the e-C3 was first to drop out. After all, it’s massively cheaper than our other two contenders and has the shortest official range. It’s also a small car designed mostly for urban and suburban runs rather than long motorway  journeys.

Still, a range of 129 miles on the day (142 miles if we assume the e-C3’s final 3% of the battery was used at the same rate) isn’t very impressive. That’s 28.7% down on the car’s official range, and the e-C3 recorded the worst efficiency of all three cars of  just 2.7 miles per kilowatt hour (mi/kWh) if we consider the amount of energy pulled from the grid, including charging losses.

It also took an epic 1hr 14min to charge from 3-80% and a further 34 minutes to get it to 100%, although, as we’ve mentioned already, we were forced to use a 50kW charger. The e-C3 can officially accept up to 100kW of power.

The EV3 averaged 2.9mi/kWh and had managed 224 miles when we plugged it in. That gives it a theoretical maximum range of 246, assuming it were to continue averaging the same efficiency and conked out completely when the battery hit 0%. That’s 32% down on the official range of 362 miles.

Charging from 10-80% took 34 minutes and we saw a peak rate of 125kW – not far behind the official numbers of 31 minutes and 130kW. The full charge from 10-100% took 1hr 20min.

And what about the Model 3? Well, despite its whopping official range of 436 miles, it seemed to suffer more than the EV3 in the searing Andalusian weather. It managed the same number of total miles but with 1% less of its indicated battery remaining, suggesting a maximum range of 244 miles if pushed to its limit in these conditions.

That’s a whopping 44% down on the official range, although it’s worth noting a couple of things. First, the percentages of remaining range between it and the EV3 were converging as we got further into the test. Earlier on in the day, after about 150 miles, the EV3 had been showing a 45% state of charge, whereas the Model 3 was at 38%.

Second, based on previous testing in cooler weather, we know that the Model 3 has a big buffer (more than 10 miles) of remaining range when its battery hits an indicated 0%. This is the first time we’ve range tested an EV3 in real-world conditions. The Model 3 was also the most efficient user of electricity in this test, averaging 3.0mi/kWh.

Unsurprisingly, the Model 3 was quickest to charge up, taking 32 minutes to go from 9-80%. A 10-80% top-up can be done in as little as 27 minutes in ideal conditions, but because of the low charge level, the car refused to activate the ‘pre-conditioning’ function before we arrived at the charging point. The extreme heat might not have helped.

We briefly saw a peak rate of 230kW (the Model 3 can accept a maximum of 250kW) and we waited 1hr 12min for the full 9-100% charge.

Effects of the heat on electric cars

So, it’s pretty clear that electric cars don’t like really hot weather – but why exactly is that? Well, for one thing, it creates a huge temperature differential between the outside of the car and the temperature you want it to be inside. And that’s before you factor in the greenhouse effect. The huge expanses of glass in any car – but particularly the Model 3 with its full-length glass roof – allow the sun in but trap heat inside that radiates off the interior surfaces.

The air-con has to work extremely hard to counter this, and that uses up energy that could otherwise be used to drive the car along. Indeed, a US study from last year found that the auxiliary load on an EV’s battery (mainly from the heating and air-con) is greater at 40-46deg than at between -4deg and 0deg. Modern EVs also have thermal management systems that cool the cells in the battery to help prevent increased degradation.

The same study found that the propulsion load (that’s the energy needed to move the car along) is only slightly lower at 40-46deg than at 6-10deg. Batteries generally operate most efficiently with the air temperature at 20-25deg, so an EV won’t be operating in its optimum window on plenty of summer days in the UK.

In theory, extremely high temperatures like we encountered in Andalusia should adversely affect charging speeds. The batteries in the EV3 and Model 3 took just a few minutes longer than claimed to go from roughly 10-80%, though, and in our experience it’s rare to match these official times, regardless of the weather.

The e-C3 took significantly longer than expected to charge; a 10-80% top-up should take around 48 minutes even from a 50kW charger. This might be because it has a less effective air-cooled battery management system (the batteries in the EV3 and Model 3 are liquid cooled) – but without repeating the test at multiple sites, it’s impossible to say for sure.

What Car? road test editor, Will Nightingale said: "If you've read anything about EVs spontaneously combusting in hot weather, fear not: that isn’t going to happen.That doesn’t mean they don’t suffer in such conditions, though; our test shows that range and efficiency plummet in extreme heat, with our EVs falling an average of more than 35% short of their official ranges.

For context, in the 2024 What Car? summer range test, a selection of 12 EVs fell an average of just 14.2% shy of their official ranges in temperatures ranging from 17- 23deg – although that test did involve a higher percentage of low-speed driving.

In fact, the shortfall in our extreme test isn’t far off what we’d expect to see when it’s cold. In our last winter range test (when it was 10-11deg), the average dip was 30%.

Luckily, the UK climate is still relatively mild. And as technology advances, we’d expect EVs to become even better at coping with extreme temperatures if they occur.

For all the latest reviews, advice and new car deals, sign up to the What Car? newsletter here

Read more: Range test: How far can electric cars really go? >>