Air quality comparison · Romania, 342 km apart
Constanţa vs Iaşi Air quality index (AQI) today
Iaşi has cleaner air than Constanţa right now: AQI 76 (Moderate) against 102 (Unhealthy for sensitive groups).
That puts them in different EPA bands, so the health advice differs today. But over the past 6 days, on modeled daily averages, Constanţa averaged AQI 37 against 53, and it was the cleaner of the two on 5 of those days. Iaşi has lost more forest since 2001. Iaşi has more tree cover.
Romania
AQI 102
Unhealthy for sensitive groups
Cleaner right now
- PM2.5
- 35.8 µg/m³2.4× WHO guideline
- Main pollutant
- PM2.5
- Source
- Ground station
- Reading
- Nov 11, 19:00 local
Romania
AQI 76
Moderate
Cleaner right now
- PM2.5
- 22.3 µg/m³1.5× 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.
Constanţa102Iaşi76
Head to head
Constanţa vs Iaşi at a glance
Iaşi is ahead on 4 of 6 measures, and Constanţa on 2. The better figure in each row is marked.
| Constanţa | Iaşi | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 102 | 76 (better) |
| PM2.5Fine particles, µg/m³. | 35.8 | 22.3 (better) |
| Past week's averageUS AQI, 6 days. | 37 (better) | 53 |
| Forest lost since 2001Within 10 km of the center. | 1 ha (better) | 93 ha |
| Tree coverWithin 2 km of the center. | 19.3% | 42.1% (better) |
| Trees still neededTo reach a healthy canopy. | 48.3K | 0 (better) |
Air quality today
What is the air like in Constanţa and Iaşi right now?
Iaşi has cleaner air than Constanţa right now: AQI 76 (Moderate) against 102 (Unhealthy for sensitive groups). PM2.5 is setting the index in both.
Constanţa's PM2.5 is about 2.4× the WHO's 24-hour guideline of 15 µg/m³. Iaşi's PM2.5 is about 1.5× the WHO's 24-hour guideline of 15 µg/m³.
Both readings come from nearby ground stations.
ConstanţaIaşi
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, Constanţa averaged AQI 37 against 53, 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
- Constanţa5Iaşi1
- Average AQI
- Constanţa37Iaşi53
- Worst day, AQI
- Constanţa57Iaşi74
The daily numbers (6 days)
| Day | Constanţa | Iaşi |
|---|---|---|
| Nov 5 | 27 | 35 |
| Nov 6 | 57 | 54 |
| Nov 7 | 26 | 30 |
| Nov 8 | 33 | 67 |
| Nov 9 | 37 | 74 |
| Nov 10 | 40 | 57 |
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 Constanţa and Iaşi today?
Constanţa (AQI 102, Unhealthy for sensitive groups): Sensitive groups should limit long or intense outdoor activity.
Iaşi (AQI 76, Moderate): Unusually sensitive people should consider limiting long outdoor exertion.
Exercise outdoors
- Constanţa
- Children, older adults and people with asthma or heart disease should cut down long or hard exercise.
- Iaşi
- Fine for most people; unusually sensitive people should take long or hard exercise easier.
Windows
- Constanţa
- Close them to keep the outside air out.
- Iaşi
- Fine to open; close them if you are sensitive to pollution.
Masks
- Constanţa
- Sensitive groups: an N95 outdoors.
- Iaşi
- Not needed for most people.
Air purifier
- Constanţa
- Run one, especially in bedrooms.
- Iaşi
- Worth running if you are sensitive.
Against everywhere else
How do Constanţa and Iaşi compare with the rest of the world?
Right now Constanţa's air is cleaner than 21% of the 5,420 places Airleaf tracks, and Iaşi's is cleaner than 33%. Within Romania, that is 5% and 37% of its 20 measured places.
Cleaner air than…
- Constanţa
- Beats 21%
- Iaşi
- Beats 33%
More tree cover than…
- Constanţa
- Beats 45%
- Iaşi
- Beats 86%
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, Constanţa or Iaşi?
Iaşi has lost more: about 93 ha of forest within 10 km of its center from 2001 to 2025, against 1 ha around Constanţa. 12 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: 2004, with under 1 ha lost.
Worst year: 2022, with 19 ha lost.
| Constanţa | Iaşi | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 1 ha (better) | 93 ha |
| Cleared for goodTurned into farms, mines or towns. | under 1 ha (better) | 12 ha |
| Recent trend2021–2025 against the five years before. | Too little to call | Too little to call |
| Main known cause | Towns and roads (27%) | Logging (80%) |
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.
Constanţa
2017: satellite photo from August 2017 of a 5 × 5 km area in the city center.
Iaşi
2017: satellite photo from August 2017 of a 5 × 5 km area about 7 km northeast of the city center.
Trees
Which has more trees, Constanţa or Iaşi?
Iaşi has more tree cover: 42.1% of the land within 2 km of its center against 19.3% around Constanţa, or about 130,674 trees against 59,359.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Constanţa | Iaşi | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 59.4K | 131K (better) |
| Trees still neededTo reach the target. Fewer is better. | 48.3K | 0 (better) |
| CO₂ absorbed each yearBy the trees already standing. | 1.3M kg | 2.9M 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
Constanţa vs Iaşi: your questions answered
Is Iaşi cleaner than Constanţa?
On air quality, yes, right now: Iaşi reads AQI 76 against 102, a gap of 26 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, Constanţa averaged AQI 37 against 53, and it was the cleaner of the two on 5 of those days.
Is it safe to exercise outdoors in Constanţa and Iaşi today?
In Constanţa, at AQI 102: Sensitive groups should limit long or intense outdoor activity. In Iaşi, at AQI 76: Unusually sensitive people should consider limiting long outdoor exertion.
Which has lost more forest, Constanţa or Iaşi?
Iaşi has lost more: about 93 ha of forest within 10 km of its center from 2001 to 2025, against 1 ha around Constanţa. 12 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Constanţa or Iaşi?
Iaşi has more tree cover: 42.1% of the land within 2 km of its center against 19.3% around Constanţa, or about 130,674 trees against 59,359. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Constanţa and Iaşi need?
Constanţa needs about 48,287 more to reach its canopy target of 35%, and Iaşi about 0 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Constanţa and Iaşi 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 Constanţa vs Iaşi 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 18, 2026), and the forest figures are published yearly.
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