Air quality comparison · United States, 1371.4 mi (2207 km) apart
Houston vs Los Angeles Air quality index (AQI) today
Los Angeles has cleaner air than Houston right now: AQI 39 (Good) against 62 (Moderate).
That puts them in different EPA bands, so the health advice differs today. Over the past 7 days, on modeled daily averages, Los Angeles averaged AQI 57 against 76, and it was the cleaner of the two on 5 of those days. Houston has lost more forest since 2001. Houston has more tree cover.
United States
AQI 62
Moderate
Cleaner right now
- PM2.5
- 15.1 µg/m³1.0× WHO guideline
- Main pollutant
- PM2.5
- Source
- Ground station
- Reading
- Nov 11, 09:00 local
United States
AQI 39
Good
Cleaner right now
- PM2.5
- 7.1 µg/m³
- Main pollutant
- PM2.5
- Source
- Ground station
- Reading
- Nov 11, 07:00 local
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Houston62Los Angeles39
Head to head
Houston vs Los Angeles at a glance
Los Angeles is ahead on 4 of 6 measures, and Houston on 2. The better figure in each row is marked.
| Houston | Los Angeles | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 62 | 39 (better) |
| PM2.5Fine particles, µg/m³. | 15.1 | 7.1 (better) |
| Past week's averageUS AQI, 7 days. | 76 | 57 (better) |
| Forest lost since 2001Within 10 km of the center. | 566 acres (229 ha) | 304 acres (123 ha) (better) |
| Tree coverWithin 1.2 mi (2 km) of the center. | 15.6% (better) | 4.5% |
| Trees still neededTo reach a healthy canopy. | 44.9K (better) | 80.0K |
Air quality today
What is the air like in Houston and Los Angeles right now?
Los Angeles has cleaner air than Houston right now: AQI 39 (Good) against 62 (Moderate). PM2.5 is setting the index in both.
Houston's PM2.5 is about 1.0× the WHO's 24-hour guideline of 15 µg/m³.
Both readings come from nearby ground stations.
HoustonLos Angeles
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).
Houston: Ground station · Carnegie Neighborhood Library, 1.3 mi (2.1 km) away · median of 40 stations. Data: OpenAQ · AirGradient, AirNow, Clarity, Air Alliance Houston, MM, Brad.
Los Angeles: Ground station · Roybal LC (8544), 0.9 mi (1.5 km) away · median of 51 stations. Data: OpenAQ · AirGradient, AirNow, Clarity, swamphag, P8Burns, Erkki, BirdNest, Frank Harper.
The past week
Which had cleaner air over the past 7 days?
Over the past 7 days, on modeled daily averages, Los Angeles averaged AQI 57 against 76, 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
- Houston1Los Angeles5
- Average AQI
- Houston76Los Angeles57
- Worst day, AQI
- Houston97Los Angeles70
The daily numbers (7 days)
| Day | Houston | Los Angeles |
|---|---|---|
| Nov 4 | 62 | 67 |
| Nov 5 | 97 | 57 |
| Nov 6 | 95 | 47 |
| Nov 7 | 77 | 46 |
| Nov 8 | 52 | 52 |
| Nov 9 | 69 | 60 |
| Nov 10 | 79 | 70 |
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 Houston and Los Angeles today?
Houston (AQI 62, Moderate): Unusually sensitive people should consider limiting long outdoor exertion.
Los Angeles (AQI 39, Good): Air quality is satisfactory for everyone.
Exercise outdoors
- Houston
- Fine for most people; unusually sensitive people should take long or hard exercise easier.
- Los Angeles
- A good day to be active outside.
Windows
- Houston
- Fine to open; close them if you are sensitive to pollution.
- Los Angeles
- Open them to air the house.
Masks
- Houston
- Not needed for most people.
- Los Angeles
- Not needed.
Air purifier
- Houston
- Worth running if you are sensitive.
- Los Angeles
- Not needed.
Against everywhere else
How do Houston and Los Angeles compare with the rest of the world?
Right now Houston's air is cleaner than 46% of the 5,420 places Airleaf tracks, and Los Angeles's is cleaner than 70%. Within United States, that is 20% and 51% of its 308 measured places.
Cleaner air than…
- Houston
- Beats 46%
- Los Angeles
- Beats 70%
More tree cover than…
- Houston
- Beats 36%
- Los Angeles
- Beats 9%
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, Houston or Los Angeles?
Houston has lost more: about 566 acres (229 ha) of forest within 10 km of its center from 2001 to 2025, against 304 acres (123 ha) around Los Angeles. 540 acres (219 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: 2011, with 180 acres (73 ha) lost.
Worst year: 2007, with 289 acres (117 ha) lost.
| Houston | Los Angeles | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 566 acres (229 ha) | 304 acres (123 ha) (better) |
| Share of its forestOf what it had in 2000. | 11% (better) | 53% |
| Cleared for goodTurned into farms, mines or towns. | 540 acres (219 ha) | 9 acres (4 ha) (better) |
| Recent trend2021–2025 against the five years before. | Too little to call | Too little to call |
| Main known cause | Towns and roads (95%) | Wildfires (96%) |
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.
Houston
2018: satellite photo from November 2018 of a 5 × 5 km area in the city center.
Los Angeles
2017: satellite photo from July 2017 of a 5 × 5 km area in the city center.
Trees
Which has more trees, Houston or Los Angeles?
Houston has more tree cover: 15.6% of the land within 1.2 mi (2 km) of its center against 4.5% around Los Angeles, or about 48,666 trees against 14,123.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Houston | Los Angeles | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 48.7K (better) | 14.1K |
| Trees still neededTo reach the target. Fewer is better. | 44.9K (better) | 80.0K |
| CO₂ absorbed each yearBy the trees already standing. | 1.1M kg (better) | 311K kg |
Tree cover on the satellite image
The same 1.2 mi (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 1.2 mi (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
Houston vs Los Angeles: your questions answered
Is Los Angeles cleaner than Houston?
On air quality, yes, right now: Los Angeles reads AQI 39 against 62, a gap of 23 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, Los Angeles averaged AQI 57 against 76, and it was the cleaner of the two on 5 of those days.
Is it safe to exercise outdoors in Houston and Los Angeles today?
In Houston, at AQI 62: Unusually sensitive people should consider limiting long outdoor exertion. In Los Angeles, at AQI 39: Air quality is satisfactory for everyone.
Which has lost more forest, Houston or Los Angeles?
Houston has lost more: about 566 acres (229 ha) of forest within 10 km of its center from 2001 to 2025, against 304 acres (123 ha) around Los Angeles. 540 acres (219 ha) of that was cleared for good, for farms, mines or towns.
Which has more trees, Houston or Los Angeles?
Houston has more tree cover: 15.6% of the land within 1.2 mi (2 km) of its center against 4.5% around Los Angeles, or about 48,666 trees against 14,123. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Houston and Los Angeles need?
Houston needs about 44,922 more to reach its canopy target of 30%, and Los Angeles about 80,030 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Houston and Los Angeles 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 Houston vs Los Angeles 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 (Oct 19, 2026 and Sep 14, 2026), and the forest figures are published yearly.
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