Air quality comparison · Vietnam, 540 km apart
Hanoi vs Huế Air quality index (AQI) today
Huế has cleaner air than Hanoi right now: AQI 27 (Good) against 162 (Unhealthy).
That puts them in different EPA bands, so the health advice differs today. Over the past 7 days, on modeled daily averages, Huế averaged AQI 58 against 82, and it was the cleaner of the two on 5 of those days. Huế has lost more forest since 2001. Huế has more tree cover.
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Hanoi162Huế27
Head to head
Hanoi vs Huế at a glance
Huế is ahead on 5 of 6 measures, and Hanoi on 1. The better figure in each row is marked.
| Hanoi | Huế | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 162 | 27 (better) |
| PM2.5Fine particles, µg/m³. | 71 | 4.8 (better) |
| Past week's averageUS AQI, 7 days. | 82 | 58 (better) |
| Forest lost since 2001Within 10 km of the center. | 11 ha (better) | 1,690 ha |
| Tree coverWithin 2 km of the center. | 18.7% | 21.2% (better) |
| Trees still neededTo reach a healthy canopy. | 65.6K | 26.7K (better) |
Air quality today
What is the air like in Hanoi and Huế right now?
Huế has cleaner air than Hanoi right now: AQI 27 (Good) against 162 (Unhealthy). PM2.5 is setting the index in both.
Hanoi's PM2.5 is about 4.7× the WHO's 24-hour guideline of 15 µg/m³.
Both readings come from nearby ground stations.
HanoiHuế
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).
Hanoi: Ground station · Số 1 đường Giải Phóng - phường Bạch Mai - ĐHBK , 2.1 km away · median of 3 stations. Data: OpenAQ · Hanoi Air Quality Monitoring Network, World Air Quality Index Project, UNIS - United Nations International School Of Hanoi.
Huế: Ground station · Thừa Thiên Huế/83 Hùng Vương, Vietnam, 100 m away. Data: World Air Quality Index Project, Vietnam Center For Environmental Monitoring Portal (cổng thông tin quan trắc môi trường).
The past week
Which had cleaner air over the past 7 days?
Over the past 7 days, on modeled daily averages, Huế averaged AQI 58 against 82, 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
- Hanoi2Huế5
- Average AQI
- Hanoi82Huế58
- Worst day, AQI
- Hanoi147Huế75
The daily numbers (7 days)
| Day | Hanoi | Huế |
|---|---|---|
| Nov 5 | 73 | 58 |
| Nov 6 | 80 | 54 |
| Nov 7 | 77 | 48 |
| Nov 8 | 91 | 55 |
| Nov 9 | 44 | 52 |
| Nov 10 | 61 | 62 |
| Nov 11 | 147 | 75 |
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 Hanoi and Huế today?
Hanoi (AQI 162, Unhealthy): Everyone should limit long outdoor exertion; sensitive groups more so.
Huế (AQI 27, Good): Air quality is satisfactory for everyone.
Exercise outdoors
- Hanoi
- Everyone should cut down long or hard exercise; sensitive groups should avoid it.
- Huế
- A good day to be active outside.
Windows
- Hanoi
- Keep them closed.
- Huế
- Open them to air the house.
Masks
- Hanoi
- Wear an N95 outdoors.
- Huế
- Not needed.
Air purifier
- Hanoi
- Run one.
- Huế
- Not needed.
Against everywhere else
How do Hanoi and Huế compare with the rest of the world?
Right now Hanoi's air is cleaner than 7% of the 5,420 places Airleaf tracks, and Huế's is cleaner than 83%. Within Vietnam, that is 0% and 73% of its 114 measured places.
Cleaner air than…
- Hanoi
- Beats 7%
- Huế
- Beats 83%
More tree cover than…
- Hanoi
- Beats 43%
- Huế
- Beats 49%
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, Hanoi or Huế?
Huế has lost more: about 1,690 ha of forest within 10 km of its center from 2001 to 2025, against 11 ha around Hanoi. 120 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 3 ha lost.
Worst year: 2021, with 232 ha lost.
| Hanoi | Huế | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 11 ha (better) | 1,690 ha |
| Cleared for goodTurned into farms, mines or towns. | 4 ha (better) | 120 ha |
| Recent trend2021–2025 against the five years before. | Too little to call | Slowing down |
| Main known cause | Towns and roads (34%) | Logging (92%) |
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.
Hanoi
2017: satellite photo from December 2017 of a 5 × 5 km area in the city center.
Huế
2017: satellite photo from April 2017 of a 5 × 5 km area about 7 km south of the city center.
Trees
Which has more trees, Hanoi or Huế?
Huế has more tree cover: 21.2% of the land within 2 km of its center against 18.7% around Hanoi, or about 64,204 trees against 57,632.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Hanoi | Huế | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 57.6K | 64.2K (better) |
| Trees still neededTo reach the target. Fewer is better. | 65.6K | 26.7K (better) |
| CO₂ absorbed each yearBy the trees already standing. | 1.3M kg | 1.4M 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
Hanoi vs Huế: your questions answered
Is Huế cleaner than Hanoi?
On air quality, yes, right now: Huế reads AQI 27 against 162, a gap of 135 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, Huế averaged AQI 58 against 82, and it was the cleaner of the two on 5 of those days.
Is it safe to exercise outdoors in Hanoi and Huế today?
In Hanoi, at AQI 162: Everyone should limit long outdoor exertion; sensitive groups more so. In Huế, at AQI 27: Air quality is satisfactory for everyone.
Which has lost more forest, Hanoi or Huế?
Huế has lost more: about 1,690 ha of forest within 10 km of its center from 2001 to 2025, against 11 ha around Hanoi. 120 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Hanoi or Huế?
Huế has more tree cover: 21.2% of the land within 2 km of its center against 18.7% around Hanoi, or about 64,204 trees against 57,632. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Hanoi and Huế need?
Hanoi needs about 65,645 more to reach its canopy target of 40%, and Huế about 26,651 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Hanoi and Huế 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 Hanoi vs Huế 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 (Aug 10, 2026 and Aug 12, 2026), and the forest figures are published yearly.
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