The Hottest London Boroughs: Where You Need AC the Most

Introduction: London Is Getting Hotter

London is one of the fastest-warming cities in Europe. Average summer temperatures in the capital have risen significantly over the past few decades, and climate projections suggest this trend will continue. The summers of 2022, 2023 and 2025 all saw temperatures exceeding 35°C in parts of London, with the 2022 heatwave breaching 40°C for the first time in UK recorded history. But the heat is not distributed evenly across the capital. Some boroughs are consistently several degrees warmer than others, thanks to a phenomenon known as the urban heat island effect.

At London AC Pro, we install and service air conditioning systems across all 32 London boroughs. We are F-Gas certified and work with Daikin, Mitsubishi Electric, Samsung, LG, Fujitsu and Toshiba. In this article, we explore which parts of London get hottest, why, and what you can do to keep your home or business comfortable.

The Urban Heat Island Effect Explained

The urban heat island (UHI) effect is a well-documented phenomenon where urban areas are significantly warmer than surrounding rural areas. In London, the UHI can add 5–10°C to nighttime temperatures compared to the countryside surrounding the capital. This means that while rural Buckinghamshire might cool to 14°C overnight, central London stays at 22–24°C, making it almost impossible to cool your home naturally by opening windows.

What Causes the UHI in London?

• Concrete, asphalt and brick — hard surfaces absorb solar energy during the day and radiate it as heat at night, keeping temperatures elevated.
• Lack of green space — trees and vegetation provide shade and cooling through evapotranspiration. Boroughs with less green cover tend to be hotter.
• Waste heat — buildings, vehicles, air conditioning systems (ironically) and industrial processes all release heat into the urban environment.
• Canyon effect — narrow streets lined with tall buildings trap heat and restrict airflow, creating localised hotspots.
• Reduced wind speed — dense urban development reduces wind speed at street level, limiting natural ventilation and cooling.

The Hottest London Boroughs

Based on climate data, heat vulnerability mapping from the Greater London Authority, and our own experience installing air conditioning across the capital, here are the London boroughs where you are most likely to need AC:

1. City of London

The Square Mile is consistently the hottest part of London. Dense commercial development, minimal green space, narrow streets and enormous quantities of waste heat from offices and data centres make the City a heat trap. Daytime temperatures here can be 3–5°C higher than outer boroughs. If you work in or live near the City, air conditioning is essential.

2. Tower Hamlets

Canary Wharf and the surrounding high-rise residential developments in Tower Hamlets are among the hottest residential areas in London. Floor-to-ceiling glazing in modern tower blocks acts as a greenhouse, trapping solar heat. Upper floors suffer the most, as hot air rises and there is no shading from adjacent buildings. We install a huge number of AC systems in Tower Hamlets flats and apartments.

3. Westminster

Westminster combines dense urban fabric, heavy traffic, and relatively little green space outside of Hyde Park and St James's Park. Areas like Paddington, Marylebone and Victoria are particularly warm. Many period properties in Westminster lack adequate natural ventilation, making AC a popular retrofit.

4. Camden

Camden Town, King's Cross and the areas around Euston are urban heat hotspots. The redevelopment around King's Cross has introduced modern glass-clad buildings that can overheat in summer. Victorian terraces in Camden also suffer from poor ventilation and south-facing rooms that bake in the afternoon sun.

5. Southwark

The South Bank, Borough, Bermondsey and Elephant and Castle are densely built areas with significant heat island effects. New-build apartments along the river are particularly affected by solar gain through large windows. Southwark is one of our busiest boroughs for residential AC installation.

6. Lambeth

Brixton, Vauxhall and Clapham North see elevated temperatures due to dense Victorian housing stock and busy road corridors. Top-floor flats and loft conversions in Lambeth are common locations for our installations.

7. Islington

Islington's Georgian and Victorian terraces, while beautiful, were not designed for modern summers. South-facing living rooms and top-floor bedrooms regularly exceed 30°C in summer. The dense urban fabric and limited green space compound the problem.

8. Hackney

Dalston, Shoreditch and Hackney Central are among the hottest parts of East London. Converted warehouses and modern apartments with industrial-style glazing are particularly prone to overheating.

9. Hammersmith and Fulham

Areas around Hammersmith, Shepherd's Bush and Fulham Broadway experience elevated temperatures due to dense housing and busy road corridors. New riverside developments with extensive glazing are especially affected.

10. Kensington and Chelsea

Despite its affluent, leafy reputation, Kensington and Chelsea includes some of London's hottest streets. Dense Victorian and Edwardian housing, basement conversions with limited ventilation, and south-facing mansion flats all contribute. This borough has one of the highest rates of residential AC installation in London.

Property Types That Overheat the Most

Regardless of which borough you live in, certain property types are more prone to overheating than others:

Top-Floor Flats and Loft Conversions

Hot air rises, and the roof absorbs solar radiation all day. Top-floor flats and loft conversions can be 5–8°C warmer than ground-floor units in the same building. If you live on the top floor, air conditioning is almost a necessity in summer.

South and West-Facing Rooms

South-facing rooms receive direct sunlight for most of the day, while west-facing rooms get the most intense afternoon sun. Large windows amplify the effect. Blinds and curtains help, but on the hottest days they are not enough.

New-Build Apartments with Floor-to-Ceiling Glazing

Modern apartments are designed to maximise natural light, but extensive glazing also maximises solar heat gain. Many new-builds in London are known to overheat, and some developers now include AC as standard — but many do not.

Period Properties with Poor Insulation

Counterintuitively, some period properties overheat in summer because their solid walls absorb and retain heat throughout the day, radiating it into the rooms at night. Combined with small windows that do not provide adequate cross-ventilation, these homes can be stifling.

Basement Flats (Yes, Really)

While basements are cooler than upper floors, they often have very limited ventilation. On humid summer days, a basement flat can feel damp, stuffy and uncomfortable. AC provides both cooling and dehumidification.

Climate Trends: It Is Only Getting Warmer

The UK Met Office projects that London's average summer temperatures will continue to rise throughout the 2020s and 2030s. Heatwaves that were once considered rare are becoming more frequent and more intense. The 40°C barrier has already been breached, and climate models suggest this could become a regular occurrence. The message is clear: investing in air conditioning now is not a luxury — it is future-proofing your home or business.

What Can You Do?

If you live or work in one of London's hotter boroughs, here are practical steps to stay cool:

1. Install air conditioning — the most effective solution. A modern split system from Daikin, Mitsubishi or Samsung provides instant, controllable cooling. Browse our residential AC installation service.
2. Improve shading — external blinds, shutters or solar film on windows can reduce solar gain by 50–80%.
3. Improve ventilation — cross-ventilation (opening windows on opposite sides of the property) helps on cooler days, but is ineffective when outside temperatures exceed 30°C.
4. Use fans alongside AC — ceiling fans or portable fans can help distribute cooled air more effectively, allowing you to set the AC a degree or two higher and save energy.
5. Close curtains and blinds during the day — especially on south and west-facing windows.

London AC Pro: Keeping All 32 Boroughs Cool

Whether you are in the heart of the City or the leafy suburbs of Richmond, London AC Pro provides expert air conditioning installation, servicing and repair across every London borough. We are F-Gas certified and install all major brands — Daikin, Mitsubishi Electric, Samsung, LG, Fujitsu and Toshiba. From single-room splits for overheating bedrooms to multi-split systems for entire homes, we have the right solution for your property. Call us on 07301 010244 or request a free quote online. Stay cool this summer — wherever you are in London.