Air quality comparison · Greece, 303 km apart
Athens vs Thessaloníki Air quality index (AQI) today
Athens has cleaner air than Thessaloníki right now: AQI 42 (Good) against 94 (Moderate).
That puts them in different EPA bands, so the health advice differs today. Over the past 7 days, on modeled daily averages, Athens averaged AQI 50 against 53, and it was the cleaner of the two on 4 of those days. Athens has lost more forest since 2001. Athens has more tree cover.
Greece
AQI 42
Good
Cleaner right now
- PM2.5
- 7.5 µg/m³
- Main pollutant
- PM2.5
- Source
- Ground station
- Reading
- Nov 11, 17:00 local
Greece
AQI 94
Moderate
Cleaner right now
- PM2.5
- 32.4 µg/m³2.2× WHO guideline
- Main pollutant
- PM2.5
- Source
- Ground station
- Reading
- Nov 11, 18:00 local
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Athens42Thessaloníki94
Head to head
Athens vs Thessaloníki at a glance
Athens is ahead on 5 of 6 measures, and Thessaloníki on 1. The better figure in each row is marked.
| Athens | Thessaloníki | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 42 (better) | 94 |
| PM2.5Fine particles, µg/m³. | 7.5 (better) | 32.4 |
| Past week's averageUS AQI, 7 days. | 50 (better) | 53 |
| Forest lost since 2001Within 10 km of the center. | 116 ha | 30 ha (better) |
| Tree coverWithin 2 km of the center. | 16.2% (better) | 7.3% |
| Trees still neededTo reach a healthy canopy. | 43.4K (better) | 54.6K |
Air quality today
What is the air like in Athens and Thessaloníki right now?
Athens has cleaner air than Thessaloníki right now: AQI 42 (Good) against 94 (Moderate). PM2.5 is setting the index in both.
Thessaloníki's PM2.5 is about 2.2× the WHO's 24-hour guideline of 15 µg/m³.
Both readings come from nearby ground stations.
AthensThessaloníki
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, Athens averaged AQI 50 against 53, 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
- Athens4Thessaloníki3
- Average AQI
- Athens50Thessaloníki53
- Worst day, AQI
- Athens61Thessaloníki69
The daily numbers (7 days)
| Day | Athens | Thessaloníki |
|---|---|---|
| Nov 4 | 48 | 36 |
| Nov 5 | 46 | 54 |
| Nov 6 | 49 | 63 |
| Nov 7 | 53 | 69 |
| Nov 8 | 38 | 50 |
| Nov 9 | 54 | 45 |
| Nov 10 | 61 | 54 |
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 Athens and Thessaloníki today?
Athens (AQI 42, Good): Air quality is satisfactory for everyone.
Thessaloníki (AQI 94, Moderate): Unusually sensitive people should consider limiting long outdoor exertion.
Exercise outdoors
- Athens
- A good day to be active outside.
- Thessaloníki
- Fine for most people; unusually sensitive people should take long or hard exercise easier.
Windows
- Athens
- Open them to air the house.
- Thessaloníki
- Fine to open; close them if you are sensitive to pollution.
Masks
- Athens
- Not needed.
- Thessaloníki
- Not needed for most people.
Air purifier
- Athens
- Not needed.
- Thessaloníki
- Worth running if you are sensitive.
Against everywhere else
How do Athens and Thessaloníki compare with the rest of the world?
Right now Athens's air is cleaner than 68% of the 5,420 places Airleaf tracks, and Thessaloníki's is cleaner than 24%. Within Greece, that is 80% and 0% of its 6 measured places.
Cleaner air than…
- Athens
- Beats 68%
- Thessaloníki
- Beats 24%
More tree cover than…
- Athens
- Beats 37%
- Thessaloníki
- Beats 15%
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, Athens or Thessaloníki?
Athens has lost more: about 116 ha of forest within 10 km of its center from 2001 to 2025, against 30 ha around Thessaloníki. 5 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 44 ha lost.
Worst year: 2020, with 16 ha lost.
| Athens | Thessaloníki | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 116 ha | 30 ha (better) |
| Share of its forestOf what it had in 2000. | 9.4% | 2% (better) |
| Cleared for goodTurned into farms, mines or towns. | 5 ha (better) | 8 ha |
| Recent trend2021–2025 against the five years before. | Too little to call | Too little to call |
| Main known cause | Wildfires (92%) | Logging (62%) |
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.
Athens
2017: satellite photo from July 2017 of a 5 × 5 km area in the city center.
Thessaloníki
2017: satellite photo from September 2017 of a 5 × 5 km area in the city center.
Trees
Which has more trees, Athens or Thessaloníki?
Athens has more tree cover: 16.2% of the land within 2 km of its center against 7.3% around Thessaloníki, or about 50,894 trees against 17,567.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Athens | Thessaloníki | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 50.9K (better) | 17.6K |
| Trees still neededTo reach the target. Fewer is better. | 43.4K (better) | 54.6K |
| CO₂ absorbed each yearBy the trees already standing. | 1.1M kg (better) | 386K 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
Athens vs Thessaloníki: your questions answered
Is Athens cleaner than Thessaloníki?
On air quality, yes, right now: Athens reads AQI 42 against 94, a gap of 52 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, Athens averaged AQI 50 against 53, and it was the cleaner of the two on 4 of those days.
Is it safe to exercise outdoors in Athens and Thessaloníki today?
In Athens, at AQI 42: Air quality is satisfactory for everyone. In Thessaloníki, at AQI 94: Unusually sensitive people should consider limiting long outdoor exertion.
Which has lost more forest, Athens or Thessaloníki?
Athens has lost more: about 116 ha of forest within 10 km of its center from 2001 to 2025, against 30 ha around Thessaloníki. 5 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Athens or Thessaloníki?
Athens has more tree cover: 16.2% of the land within 2 km of its center against 7.3% around Thessaloníki, or about 50,894 trees against 17,567. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Athens and Thessaloníki need?
Athens needs about 43,354 more to reach its canopy target of 30%, and Thessaloníki about 54,627 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Athens and Thessaloníki 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 Athens vs Thessaloníki 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 18, 2026 and Sep 14, 2026), and the forest figures are published yearly.
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