Air quality comparison · United Kingdom, 141.1 mi (227 km) apart
London vs Sheffield Air quality index (AQI) today
Sheffield has cleaner air than London right now: AQI 38 (Good) against 71 (Moderate).
That puts them in different EPA bands, so the health advice differs today. Over the past 7 days, on modeled daily averages, Sheffield averaged AQI 65 against 78, and it was the cleaner of the two on 5 of those days. Sheffield has lost more forest since 2001. Sheffield has more tree cover.
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
London71Sheffield38
Head to head
London vs Sheffield at a glance
Sheffield is ahead on 5 of 6 measures, and London on 1. The better figure in each row is marked.
| London | Sheffield | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 71 | 38 (better) |
| PM2.5Fine particles, µg/m³. | 20 | 6.9 (better) |
| Past week's averageUS AQI, 7 days. | 78 | 65 (better) |
| Forest lost since 2001Within 10 km of the center. | 9 ha (better) | 163 ha |
| Tree coverWithin 1.2 mi (2 km) of the center. | 18.4% | 26.3% (better) |
| Trees still neededTo reach a healthy canopy. | 33.5K | 11.6K (better) |
Air quality today
What is the air like in London and Sheffield right now?
Sheffield has cleaner air than London right now: AQI 38 (Good) against 71 (Moderate). PM2.5 is setting the index in both.
London's PM2.5 is about 1.3× the WHO's 24-hour guideline of 15 µg/m³.
Both readings come from nearby ground stations.
LondonSheffield
Concentrations at the same moment as the index above, for the pollutants both places report. Lower is better. The dark marks on the PM2.5 and PM10 rows show the WHO's 24-hour guidelines (15 and 45 µg/m³).
The past week
Which had cleaner air over the past 7 days?
Over the past 7 days, on modeled daily averages, Sheffield averaged AQI 65 against 78, and it was the cleaner of the two on 5 of those days. A single reading can catch a city on a bad afternoon; the week says whether it was the weather or the place.
- Cleaner days
- London2Sheffield5
- Average AQI
- London78Sheffield65
- Worst day, AQI
- London100Sheffield83
The daily numbers (7 days)
| Day | London | Sheffield |
|---|---|---|
| Nov 5 | 53 | 33 |
| Nov 6 | 89 | 62 |
| Nov 7 | 100 | 75 |
| Nov 8 | 92 | 78 |
| Nov 9 | 82 | 83 |
| Nov 10 | 72 | 75 |
| Nov 11 | 59 | 50 |
Daily averages from the CAMS atmospheric model for both places, so the week compares like with like. They can differ from today's reading at the top of the page wherever that comes from a ground station.
What it means today
Is it safe to go outside in London and Sheffield today?
London (AQI 71, Moderate): Unusually sensitive people should consider limiting long outdoor exertion.
Sheffield (AQI 38, Good): Air quality is satisfactory for everyone.
Exercise outdoors
- London
- Fine for most people; unusually sensitive people should take long or hard exercise easier.
- Sheffield
- A good day to be active outside.
Windows
- London
- Fine to open; close them if you are sensitive to pollution.
- Sheffield
- Open them to air the house.
Masks
- London
- Not needed for most people.
- Sheffield
- Not needed.
Air purifier
- London
- Worth running if you are sensitive.
- Sheffield
- Not needed.
Against everywhere else
How do London and Sheffield compare with the rest of the world?
Right now London's air is cleaner than 37% of the 5,420 places Airleaf tracks, and Sheffield's is cleaner than 73%. Within United Kingdom, that is 25% and 82% of its 92 measured places.
Cleaner air than…
- London
- Beats 37%
- Sheffield
- Beats 73%
More tree cover than…
- London
- Beats 43%
- Sheffield
- Beats 61%
Includes model estimates as well as station readings, so it can differ from our most polluted and cleanest air rankings, which use station readings only.
Deforestation · 2001–2025
Which has lost more forest, London or Sheffield?
Sheffield has lost more: about 163 ha of forest within 10 km of its center from 2001 to 2025, against 9 ha around London. 11 ha of that was cleared for good, for farms, mines or towns.
Measured within 10 km of each center, from the yearly satellite maps of forest loss: a wider circle than the one for tree cover, because forest is usually lost at a city's edges.
Worst year: 2008, with 3 ha lost.
Worst year: 2022, with 26 ha lost.
| London | Sheffield | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 9 ha (better) | 163 ha |
| Share of its forestOf what it had in 2000. | under 1% (better) | 2.9% |
| Cleared for goodTurned into farms, mines or towns. | under 1 ha (better) | 11 ha |
| Recent trend2021–2025 against the five years before. | Too little to call | Too little to call |
| Main known cause | Towns and roads (8.9%) | Logging (83%) |
Satellite timelapses
Watch both change, year by year
A clear satellite photo a year of the land around each city. Press play, turn on the forest cleared since the first year, or drag the before and after.
London
2017: satellite photo from August 2017 of a 5 × 5 km area in the city center.
Sheffield
2017: satellite photo from July 2017 of a 5 × 5 km area about 7 km west of the city center.
Trees
Which has more trees, London or Sheffield?
Sheffield has more tree cover: 26.3% of the land within 1.2 mi (2 km) of its center against 18.4% around London, or about 82,459 trees against 53,065.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| London | Sheffield | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 53.1K | 82.5K (better) |
| Trees still neededTo reach the target. Fewer is better. | 33.5K | 11.6K (better) |
| CO₂ absorbed each yearBy the trees already standing. | 1.2M kg | 1.8M kg (better) |
Tree cover on the satellite image
The same 1.2 mi (2 km) radius around each center, with the tree cover the satellite found marked on it.
Reading these numbers
How this comparison is made
Air quality index
The US EPA index, computed from current pollutant concentrations: ground stations where a place has them nearby, and the CAMS atmospheric model everywhere else. It moves hour to hour, so it is a snapshot rather than a verdict on either place. The guideline marks are from the WHO's 2021 air quality guidelines.
Trees and forest
Tree cover is the share of ground under canopy within 1.2 mi (2 km) of each center, read from Sentinel-2 satellite imagery at 10 m detail. It measures that circle, not the whole municipality, which is what makes the two comparable. Forest loss comes from the University of Maryland's Global Forest Change maps.
More on the method on the About Airleaf page.
Frequently asked
London vs Sheffield: your questions answered
Is Sheffield cleaner than London?
On air quality, yes, right now: Sheffield reads AQI 38 against 71, a gap of 33 points on the US EPA index. This is a live reading rather than an annual average, so it can reverse within a day. Over the past 7 days, on modeled daily averages, Sheffield averaged AQI 65 against 78, and it was the cleaner of the two on 5 of those days.
Is it safe to exercise outdoors in London and Sheffield today?
In London, at AQI 71: Unusually sensitive people should consider limiting long outdoor exertion. In Sheffield, at AQI 38: Air quality is satisfactory for everyone.
Which has lost more forest, London or Sheffield?
Sheffield has lost more: about 163 ha of forest within 10 km of its center from 2001 to 2025, against 9 ha around London. 11 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, London or Sheffield?
Sheffield has more tree cover: 26.3% of the land within 1.2 mi (2 km) of its center against 18.4% around London, or about 82,459 trees against 53,065. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do London and Sheffield need?
London needs about 33,454 more to reach its canopy target of 30%, and Sheffield about 11,601 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are London and Sheffield measured the same way?
The method is the same: the US EPA index for air, and Sentinel-2 satellite imagery at 10 m detail over an identical radius for trees. Both readings come from nearby ground stations. Nothing is adjusted for population, city limits or climate.
How often does the London vs Sheffield comparison update?
The air readings refresh about once an hour, and each reading's local time is shown at the top of the page. Tree cover comes from the latest clear satellite image of each area (Aug 25, 2026 and Aug 23, 2026), and the forest figures are published yearly.
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