Air quality comparison · Czechia, 186 km apart
Brno vs Prague Air quality index (AQI) today
Brno has cleaner air than Prague right now: AQI 63 (Moderate) against 72 (Moderate).
Both sit in the same EPA band, so the health advice is the same for each today. Over the past 7 days, on modeled daily averages, Brno averaged AQI 74 against 88, and it was the cleaner of the two on 6 of those days. Brno has lost more forest since 2001. Prague has more tree cover.
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Brno63Prague72
Head to head
Brno vs Prague at a glance
Brno and Prague are level, each ahead on 3 of 6 measures. The better figure in each row is marked.
| Brno | Prague | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 63 (better) | 72 |
| PM2.5Fine particles, µg/m³. | 15.5 (better) | 20.4 |
| Past week's averageUS AQI, 7 days. | 74 (better) | 88 |
| Forest lost since 2001Within 10 km of the center. | 807 ha | 93 ha (better) |
| Tree coverWithin 2 km of the center. | 25.4% | 26.1% (better) |
| Trees still neededTo reach a healthy canopy. | 14.5K | 11.3K (better) |
Air quality today
What is the air like in Brno and Prague right now?
Brno has cleaner air than Prague right now: AQI 63 (Moderate) against 72 (Moderate). PM2.5 is setting the index in both.
Brno's PM2.5 is about 1.0× the WHO's 24-hour guideline of 15 µg/m³. Prague's PM2.5 is about 1.4× the WHO's 24-hour guideline of 15 µg/m³.
Both readings come from nearby ground stations.
BrnoPrague
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).
Brno: Ground station · Brno - Detska nemocnice, 1 km away · median of 5 stations. Data: OpenAQ · EEA, World Air Quality Index Project, Czech Hydrometeorological Institute (Český hydrometeorologický ústav).
Prague: Ground station · Praha 2-Riegrovy sady, 1.7 km away · median of 12 stations. Data: OpenAQ · EEA.
The past week
Which had cleaner air over the past 7 days?
Over the past 7 days, on modeled daily averages, Brno averaged AQI 74 against 88, and it was the cleaner of the two on 6 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
- Brno6Prague1
- Average AQI
- Brno74Prague88
- Worst day, AQI
- Brno90Prague108
The daily numbers (7 days)
| Day | Brno | Prague |
|---|---|---|
| Nov 4 | 57 | 68 |
| Nov 5 | 74 | 70 |
| Nov 6 | 77 | 102 |
| Nov 7 | 73 | 79 |
| Nov 8 | 73 | 90 |
| Nov 9 | 90 | 108 |
| Nov 10 | 73 | 98 |
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 Brno and Prague 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 Brno and Prague compare with the rest of the world?
Right now Brno's air is cleaner than 45% of the 5,420 places Airleaf tracks, and Prague's is cleaner than 36%. Within Czechia, that is 50% and 25% of its 5 measured places.
Cleaner air than…
- Brno
- Beats 45%
- Prague
- Beats 36%
More tree cover than…
- Brno
- Beats 59%
- Prague
- Beats 60%
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, Brno or Prague?
Brno has lost more: about 807 ha of forest within 10 km of its center from 2001 to 2025, against 93 ha around Prague. 40 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: 2005, with 144 ha lost.
Worst year: 2010, with 11 ha lost.
| Brno | Prague | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 807 ha | 93 ha (better) |
| Share of its forestOf what it had in 2000. | 8.5% | 1.8% (better) |
| Cleared for goodTurned into farms, mines or towns. | 40 ha | 32 ha (better) |
| Recent trend2021–2025 against the five years before. | Slowing down | Too little to call |
| Main known cause | Logging (93%) | Logging (51%) |
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.
Brno
2018: satellite photo from September 2018 of a 5 × 5 km area about 7 km northeast of the city center.
Prague
2017: satellite photo from August 2017 of a 5 × 5 km area in the city center.
Trees
Which has more trees, Brno or Prague?
Prague has more tree cover: 26.1% of the land within 2 km of its center against 25.4% around Brno, or about 75,846 trees against 79,796.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Brno | Prague | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 79.8K (better) | 75.8K |
| Trees still neededTo reach the target. Fewer is better. | 14.5K | 11.3K (better) |
| CO₂ absorbed each yearBy the trees already standing. | 1.8M kg (better) | 1.7M 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
Brno vs Prague: your questions answered
Is Brno cleaner than Prague?
On air quality, yes, right now: Brno reads AQI 63 against 72, a gap of 9 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, Brno averaged AQI 74 against 88, and it was the cleaner of the two on 6 of those days.
Is it safe to exercise outdoors in Brno and Prague today?
The advice is the same for both today. Unusually sensitive people should consider limiting long outdoor exertion. Brno reads AQI 63 and Prague reads AQI 72.
Which has lost more forest, Brno or Prague?
Brno has lost more: about 807 ha of forest within 10 km of its center from 2001 to 2025, against 93 ha around Prague. 40 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Brno or Prague?
Prague has more tree cover: 26.1% of the land within 2 km of its center against 25.4% around Brno, or about 75,846 trees against 79,796. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Brno and Prague need?
Brno needs about 14,451 more to reach its canopy target of 30%, and Prague about 11,333 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Brno and Prague 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 Brno vs Prague 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 8, 2026 and Sep 19, 2026), and the forest figures are published yearly.
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