London in July is a bit of a trickster. You see the photos of people lounging in St. James’s Park with ice creams, looking all summery and bright, and you think, "Okay, cool, it’s basically like a Mediterranean summer."
Not quite.
Honestly, the temperature in London July is one of the most unpredictable things you’ll ever have to pack for. One day you’re literally melting on the Central Line—which, fun fact, is basically a subterranean oven—and the next you’re ducking into a pub because a random "summer shower" has turned into a freezing downpour.
If you’re planning a trip, or you just moved here and are wondering why everyone is complaining about the heat when it’s only 24°C, here is the ground truth.
The Raw Numbers vs. How It Actually Feels
On paper, the stats look mild. The Met Office generally puts the average high for July around 23°C (73°F) and the average low at 14°C (57°F).
💡 You might also like: Finding Your Way: A Latitude and Longitude Map of the United States With Cities Explained
Sounds pleasant, right? Like a light sweater evening?
Well, those averages are becoming increasingly misleading. In July 2025, for example, the UK saw its fifth warmest July on record. We had a massive spike where temperatures in the Southeast hit 35.8°C (96.4°F). When London hits those mid-30s, it doesn’t feel like 30 degrees in Spain. It feels like you are trapped in a humid, airless brick.
There’s this thing called the Urban Heat Island (UHI) effect. Basically, London’s concrete, asphalt, and millions of people trap heat like a giant radiator. The city center can be up to 10°C warmer than the leafy suburbs or the rural areas just outside the M25. This is why you’ll see Londoners looking absolutely haggard at 28°C while tourists from Texas are wondering where the "real" heat is. We don’t have air conditioning in our homes, and our Victorian infrastructure was built to keep heat in, not let it out.
What the 2025 Data Taught Us
Looking back at the most recent July, the daily maximums were roughly 2.0°C above the long-term average in Southern England.
📖 Related: Water temperature san francisco bay area: Why the "Golden Gate" is colder than you think
- Heathrow and Kew Gardens: These are the usual suspects for the highest readings. They often hit 32°C to 35°C during brief heatwaves.
- Nighttime "Tropical Nights": We’re seeing more nights where the temperature doesn’t drop below 20°C. In London, this is a disaster. Without AC, your bedroom stays at 26°C all night. You won't sleep. You’ll just lie there listening to the distant hum of a cheap desk fan.
- Rainfall: July 2025 was actually quite dry in the South, but London still gets those thundery outbreaks. When it rains in July, it’s usually heavy and fast.
Why 25°C in London Feels Like 35°C Elsewhere
Humidity is the silent killer here. London in July is often "muggy."
When the moisture levels rise, your sweat doesn’t evaporate. You just get that sticky, "I need a shower immediately" feeling the moment you walk out of your hotel. If you’re taking the Tube, specifically the older lines like the Bakerloo or Northern, the temperatures can reach 30°C+ underground even on a moderately warm day.
"I've lived in Dubai and I've lived in London. I'd honestly rather do 40 degrees in the desert than 32 degrees on the Victoria Line in July. There is just nowhere for the air to go." — Common sentiment among London expats.
The Microclimates
If you want to escape the worst of the temperature in London July, you have to pick your spots.
The "Green Lungs" of the city—places like Richmond Park, Hampstead Heath, or even the Royal Parks in the center—are significantly cooler. Research into London’s urban forests shows that areas with high tree density can lower the local "thermal comfort index" by a noticeable margin. If the forecast says 30°C, head to the shade of the oaks in Greenwich Park. It might only feel like 26°C there.
Packing for the July Rollercoaster
You’ve heard it before: layers. But let’s be specific.
Don't just bring "summer clothes." You need a mix. Most days will be fine for t-shirts and shorts, but you'll feel like a bit of a "sweaty tourist" if you don't have a backup plan for the evening.
- Linen is your best friend. It’s breathable and looks intentional even when it’s wrinkled.
- The "Emergency Brolly." A small, windproof umbrella is non-negotiable. July is prime "thunderstorm after a hot day" season.
- Lightweight Jacket. Once the sun goes down, the temperature can drop 10 degrees in an hour. A denim jacket or a light trench is the London uniform for a reason.
- Footwear. Don't wear flip-flops in the city. Your feet will be black with soot by 4 PM. Stick to breathable sneakers or sturdy sandals with straps.
Actionable Tips for Surviving the Heat
If you find yourself in London during a July heatwave, here’s how to handle it like a pro:
- Download the "Cool Spaces" Map: The Mayor of London’s office usually publishes a map of libraries, museums, and galleries that are air-conditioned and free to enter.
- Hydration Stations: Don't buy plastic water bottles. There are over 100 Refill London stations across the city where you can get chilled, filtered water for free.
- Travel Strategy: Use the Elizabeth Line or the overground trains whenever possible. These are modern and have decent air conditioning. Avoid the Central Line at all costs if it’s over 25°C.
- The Pharmacy Secret: If you're struggling with the heat at night, go to a Boots or Superdrug and look for "cooling mists" or menthol-based body gels. They’re a lifesaver when you’re trying to sleep in a non-AC Airbnb.
- Check the "Feels Like" Temp: Always look at the "feels like" temperature on your weather app, not just the raw number. If the humidity is over 60%, add 3-4 degrees to your mental calculation.
London in July is beautiful, but it’s a workout. Respect the humidity, avoid the deep Tube lines during rush hour, and always, always have a light jacket in your bag for when the sun inevitably ducks behind a cloud.
🔗 Read more: Why the La Junta tarantula migration is Colorado’s most misunderstood wildlife spectacle
To stay ahead of the weather, check the Met Office's 5-day forecast specifically for "Greater London" rather than just "UK" averages, as the city often behaves like its own separate climate zone. Keep an eye on the Air Quality Index too; hot July days in the city often see a spike in pollution levels, which can make the heat feel even more oppressive if you have asthma or hay fever.