Air quality comparison · Slovakia, 238 km apart
Košice vs Nitra Air quality index (AQI) today
Nitra has cleaner air than Košice right now: AQI 61 (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 7 days, on modeled daily averages, Košice averaged AQI 62 against 64, and it was the cleaner of the two on 4 of those days. Košice has lost more forest since 2001. Nitra has more tree cover.
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Košice77Nitra61
Head to head
Košice vs Nitra at a glance
Nitra is ahead on 5 of 6 measures, and Košice on 1. The better figure in each row is marked.
| Košice | Nitra | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 77 | 61 (better) |
| PM2.5Fine particles, µg/m³. | 23.1 | 14.2 (better) |
| Past week's averageUS AQI, 7 days. | 62 (better) | 64 |
| Forest lost since 2001Within 10 km of the center. | 385 ha | 230 ha (better) |
| Tree coverWithin 2 km of the center. | 20.2% | 35.1% (better) |
| Trees still neededTo reach a healthy canopy. | 30.8K | 0 (better) |
Air quality today
What is the air like in Košice and Nitra right now?
Nitra has cleaner air than Košice right now: AQI 61 (Moderate) against 77 (Moderate). PM2.5 is setting the index in both.
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.
KošiceNitra
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?
But over the past 7 days, on modeled daily averages, Košice averaged AQI 62 against 64, and it was the cleaner of the two on 4 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
- Košice4Nitra3
- Average AQI
- Košice62Nitra64
- Worst day, AQI
- Košice82Nitra79
The daily numbers (7 days)
| Day | Košice | Nitra |
|---|---|---|
| Nov 4 | 46 | 61 |
| Nov 5 | 52 | 65 |
| Nov 6 | 55 | 79 |
| Nov 7 | 55 | 61 |
| Nov 8 | 66 | 58 |
| Nov 9 | 80 | 63 |
| Nov 10 | 82 | 63 |
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 Košice and Nitra 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 Košice and Nitra compare with the rest of the world?
Right now Košice's air is cleaner than 33% of the 5,420 places Airleaf tracks, and Nitra's is cleaner than 47%. Within Slovakia, that is 0% and 100% of its 5 measured places.
Cleaner air than…
- Košice
- Beats 33%
- Nitra
- Beats 47%
More tree cover than…
- Košice
- Beats 47%
- Nitra
- Beats 77%
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, Košice or Nitra?
Košice has lost more: about 385 ha of forest within 10 km of its center from 2001 to 2025, against 230 ha around Nitra. 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: 2017, with 34 ha lost.
Worst year: 2009, with 21 ha lost.
| Košice | Nitra | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 385 ha | 230 ha (better) |
| Share of its forestOf what it had in 2000. | 3.6% (better) | 5.1% |
| Cleared for goodTurned into farms, mines or towns. | 31 ha | 18 ha (better) |
| Recent trend2021–2025 against the five years before. | Too little to call | Too little to call |
| Main known cause | Logging (89%) | Logging (90%) |
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.
Košice
2017: satellite photo from August 2017 of a 5 × 5 km area about 7 km east of the city center.
Nitra
2017: satellite photo from August 2017 of a 5 × 5 km area about 7 km west of the city center.
Trees
Which has more trees, Košice or Nitra?
Nitra has more tree cover: 35.1% of the land within 2 km of its center against 20.2% around Košice, or about 110,160 trees against 63,460.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Košice | Nitra | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 63.5K | 110K (better) |
| Trees still neededTo reach the target. Fewer is better. | 30.8K | 0 (better) |
| CO₂ absorbed each yearBy the trees already standing. | 1.4M kg | 2.4M kg (better) |
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
Košice vs Nitra: your questions answered
Is Nitra cleaner than Košice?
On air quality, yes, right now: Nitra reads AQI 61 against 77, a gap of 16 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 7 days, on modeled daily averages, Košice averaged AQI 62 against 64, and it was the cleaner of the two on 4 of those days.
Is it safe to exercise outdoors in Košice and Nitra today?
The advice is the same for both today. Unusually sensitive people should consider limiting long outdoor exertion. Košice reads AQI 77 and Nitra reads AQI 61.
Which has lost more forest, Košice or Nitra?
Košice has lost more: about 385 ha of forest within 10 km of its center from 2001 to 2025, against 230 ha around Nitra. 31 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Košice or Nitra?
Nitra has more tree cover: 35.1% of the land within 2 km of its center against 20.2% around Košice, or about 110,160 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 Košice and Nitra need?
Košice needs about 30,788 more to reach its canopy target of 30%, and Nitra about 0 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Košice and Nitra 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 Košice vs Nitra 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 7, 2026 and Sep 18, 2026), and the forest figures are published yearly.
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