Air quality comparison · Finland, 533 km apart
Oulu vs Turku Air quality index (AQI) today
Oulu has cleaner air than Turku right now: AQI 42 (Good) against 44 (Good).
Both sit in the same EPA band, so the health advice is the same for each today. Over the past 6 days, on modeled daily averages, Oulu averaged AQI 9 against 17, and it was the cleaner of the two on 6 of those days. Oulu has lost more forest since 2001. Turku has more tree cover.
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Oulu42Turku44
Head to head
Oulu vs Turku at a glance
Oulu is ahead on 3 of 6 measures, and Turku on 2. The better figure in each row is marked.
| Oulu | Turku | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 42 (better) | 44 |
| PM2.5Fine particles, µg/m³. | 7.6 (better) | 7.9 |
| Past week's averageUS AQI, 6 days. | 9 (better) | 17 |
| Forest lost since 2001Within 10 km of the center. | 3,500 ha | 1,620 ha (better) |
| Tree coverWithin 2 km of the center. | 37.5% | 40.1% (better) |
| Trees still neededTo reach a healthy canopy. | 0 | 0 |
Air quality today
What is the air like in Oulu and Turku right now?
Oulu has cleaner air than Turku right now: AQI 42 (Good) against 44 (Good). PM2.5 is setting the index in both.
Both readings come from nearby ground stations.
OuluTurku
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).
Oulu: Ground station · Nokela, 2 km away · median of 3 stations. Data: OpenAQ · EEA.
Turku: Ground station · Kauppatori 2, Turku, Finland, 100 m away · median of 2 stations. Data: World Air Quality Index Project, Ilmanlaatu - Air Quality in finland.
The past week
Which had cleaner air over the past 6 days?
Over the past 6 days, on modeled daily averages, Oulu averaged AQI 9 against 17, 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
- Oulu6Turku0
- Average AQI
- Oulu9Turku17
- Worst day, AQI
- Oulu11Turku34
The daily numbers (6 days)
| Day | Oulu | Turku |
|---|---|---|
| Nov 5 | 9 | 11 |
| Nov 6 | 8 | 14 |
| Nov 7 | 8 | 13 |
| Nov 8 | 9 | 12 |
| Nov 9 | 8 | 18 |
| Nov 10 | 11 | 34 |
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 Oulu and Turku today?
Air quality is satisfactory for everyone. Both are in the same EPA band today (Good), so the advice is the same.
Exercise outdoors
A good day to be active outside.
Windows
Open them to air the house.
Masks
Not needed.
Air purifier
Not needed.
Against everywhere else
How do Oulu and Turku compare with the rest of the world?
Right now Oulu's air is cleaner than 67% of the 5,420 places Airleaf tracks, and Turku's is cleaner than 66%. Within Finland, that is 75% and 63% of its 9 measured places.
Cleaner air than…
- Oulu
- Beats 67%
- Turku
- Beats 66%
More tree cover than…
- Oulu
- Beats 80%
- Turku
- Beats 84%
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, Oulu or Turku?
Oulu has lost more: about 3,500 ha of forest within 10 km of its center from 2001 to 2025, against 1,620 ha around Turku. 2,230 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 371 ha lost.
Worst year: 2017, with 206 ha lost.
| Oulu | Turku | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 3,500 ha | 1,620 ha (better) |
| Share of its forestOf what it had in 2000. | 25% | 12% (better) |
| Cleared for goodTurned into farms, mines or towns. | 2,230 ha | 919 ha (better) |
| Recent trend2021–2025 against the five years before. | Slowing down | Slowing down |
| Main known cause | Towns and roads (60%) | Towns and roads (56%) |
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.
Oulu
2017: satellite photo from September 2017 of a 5 × 5 km area about 7 km east of the city center.
Turku
2017: satellite photo from August 2017 of a 5 × 5 km area about 7 km north of the city center.
Trees
Which has more trees, Oulu or Turku?
Turku has more tree cover: 40.1% of the land within 2 km of its center against 37.5% around Oulu, or about 124,214 trees against 102,377.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Oulu | Turku | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 102K | 124K (better) |
| Trees still neededTo reach the target. Fewer is better. | 0 | 0 |
| CO₂ absorbed each yearBy the trees already standing. | 2.3M kg | 2.7M 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
Oulu vs Turku: your questions answered
Is Oulu cleaner than Turku?
On air quality, yes, right now: Oulu reads AQI 42 against 44, a gap of 2 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 6 days, on modeled daily averages, Oulu averaged AQI 9 against 17, and it was the cleaner of the two on 6 of those days.
Is it safe to exercise outdoors in Oulu and Turku today?
The advice is the same for both today. Air quality is satisfactory for everyone. Oulu reads AQI 42 and Turku reads AQI 44.
Which has lost more forest, Oulu or Turku?
Oulu has lost more: about 3,500 ha of forest within 10 km of its center from 2001 to 2025, against 1,620 ha around Turku. 2,230 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Oulu or Turku?
Turku has more tree cover: 40.1% of the land within 2 km of its center against 37.5% around Oulu, or about 124,214 trees against 102,377. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Oulu and Turku need?
Oulu needs about 0 more to reach its canopy target of 30%, and Turku about 0 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Oulu and Turku 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 Oulu vs Turku 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 11, 2026 and Sep 6, 2026), and the forest figures are published yearly.
Keep going
Compare them with somewhere else
Build your own
Compare Oulu with somewhere else
This place
Oulu