Air quality comparison · Slovakia, 313 km apart
Bratislava vs Košice Air quality index (AQI) today
Bratislava has cleaner air than Košice right now: AQI 63 (Moderate) against 77 (Moderate).
Both sit in the same EPA band, so the health advice is the same for each today. But over the past 6 days, on modeled daily averages, Košice averaged AQI 65 against 79, and it was the cleaner of the two on 5 of those days. Košice has lost more forest since 2001. Bratislava has more tree cover.
Slovakia
AQI 63
Moderate
Cleaner right now
- PM2.5
- 15.6 µg/m³1.0× WHO guideline
- Main pollutant
- PM2.5
- Source
- Ground station
- Reading
- Nov 11, 16:00 local
Slovakia
AQI 77
Moderate
Cleaner right now
- PM2.5
- 23.1 µg/m³1.5× WHO guideline
- Main pollutant
- PM2.5
- Source
- Ground station
- Reading
- Nov 11, 16:00 local
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Bratislava63Košice77
Head to head
Bratislava vs Košice at a glance
Bratislava is ahead on 5 of 6 measures, and Košice on 1. The better figure in each row is marked.
| Bratislava | Košice | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 63 (better) | 77 |
| PM2.5Fine particles, µg/m³. | 15.6 (better) | 23.1 |
| Past week's averageUS AQI, 6 days. | 79 | 65 (better) |
| Forest lost since 2001Within 10 km of the center. | 356 ha (better) | 385 ha |
| Tree coverWithin 2 km of the center. | 40.8% (better) | 20.2% |
| Trees still neededTo reach a healthy canopy. | 0 (better) | 30.8K |
Air quality today
What is the air like in Bratislava and Košice right now?
Bratislava has cleaner air than Košice right now: AQI 63 (Moderate) against 77 (Moderate). PM2.5 is setting the index in both.
Bratislava's PM2.5 is about 1.0× the WHO's 24-hour guideline of 15 µg/m³. Košice's PM2.5 is about 1.5× the WHO's 24-hour guideline of 15 µg/m³.
Both readings come from nearby ground stations.
BratislavaKošice
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 6 days?
But over the past 6 days, on modeled daily averages, Košice averaged AQI 65 against 79, 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
- Bratislava1Košice5
- Average AQI
- Bratislava79Košice65
- Worst day, AQI
- Bratislava86Košice82
The daily numbers (6 days)
| Day | Bratislava | Košice |
|---|---|---|
| Nov 5 | 72 | 52 |
| Nov 6 | 86 | 55 |
| Nov 7 | 77 | 55 |
| Nov 8 | 75 | 66 |
| Nov 9 | 86 | 80 |
| Nov 10 | 76 | 82 |
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 Bratislava and Košice today?
Unusually sensitive people should consider limiting long outdoor exertion. Both are in the same EPA band today (Moderate), so the advice is the same.
Exercise outdoors
Fine for most people; unusually sensitive people should take long or hard exercise easier.
Windows
Fine to open; close them if you are sensitive to pollution.
Masks
Not needed for most people.
Air purifier
Worth running if you are sensitive.
Against everywhere else
How do Bratislava and Košice compare with the rest of the world?
Right now Bratislava's air is cleaner than 45% of the 5,420 places Airleaf tracks, and Košice's is cleaner than 33%. Within Slovakia, that is 50% and 0% of its 5 measured places.
Cleaner air than…
- Bratislava
- Beats 45%
- Košice
- Beats 33%
More tree cover than…
- Bratislava
- Beats 85%
- Košice
- Beats 47%
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, Bratislava or Košice?
Košice has lost more: about 385 ha of forest within 10 km of its center from 2001 to 2025, against 356 ha around Bratislava. 31 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: 2010, with 91 ha lost.
Worst year: 2017, with 34 ha lost.
| Bratislava | Košice | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 356 ha (better) | 385 ha |
| Share of its forestOf what it had in 2000. | 3.8% | 3.6% (better) |
| Cleared for goodTurned into farms, mines or towns. | 28 ha (better) | 31 ha |
| Recent trend2021–2025 against the five years before. | Too little to call | Too little to call |
| Main known cause | Logging (89%) | Logging (89%) |
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.
Bratislava
2017: satellite photo from August 2017 of a 5 × 5 km area about 6 km southwest of the city center.
Košice
2017: satellite photo from August 2017 of a 5 × 5 km area about 7 km east of the city center.
Trees
Which has more trees, Bratislava or Košice?
Bratislava has more tree cover: 40.8% of the land within 2 km of its center against 20.2% around Košice, or about 116,769 trees against 63,460.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Bratislava | Košice | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 117K (better) | 63.5K |
| Trees still neededTo reach the target. Fewer is better. | 0 (better) | 30.8K |
| CO₂ absorbed each yearBy the trees already standing. | 2.6M kg (better) | 1.4M kg |
Tree cover on the satellite image
The same 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 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
Bratislava vs Košice: your questions answered
Is Bratislava cleaner than Košice?
On air quality, yes, right now: Bratislava reads AQI 63 against 77, a gap of 14 points on the US EPA index. This is a live reading rather than an annual average, so it can reverse within a day. But over the past 6 days, on modeled daily averages, Košice averaged AQI 65 against 79, and it was the cleaner of the two on 5 of those days.
Is it safe to exercise outdoors in Bratislava and Košice today?
The advice is the same for both today. Unusually sensitive people should consider limiting long outdoor exertion. Bratislava reads AQI 63 and Košice reads AQI 77.
Which has lost more forest, Bratislava or Košice?
Košice has lost more: about 385 ha of forest within 10 km of its center from 2001 to 2025, against 356 ha around Bratislava. 31 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Bratislava or Košice?
Bratislava has more tree cover: 40.8% of the land within 2 km of its center against 20.2% around Košice, or about 116,769 trees against 63,460. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Bratislava and Košice need?
Bratislava needs about 0 more to reach its canopy target of 30%, and Košice about 30,788 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Bratislava and Košice 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 Bratislava vs Košice 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 (Sep 16, 2026 and Sep 7, 2026), and the forest figures are published yearly.
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