City Air Quality

San Jose, California, United States

San Jose air quality today

Current values look suitable for ordinary outdoor activity for most people.

Data: Current Open-Meteo model estimate

Practical guidance

Outdoor

Current values look suitable for ordinary outdoor activity for most people.

Why: Low AQI and low pollutant levels support this guidance.

Running

Current values look suitable for an easy outdoor run.

Why: Low AQI and low pollutant levels support this guidance.

Ventilation

Current values support brief ventilation.

Why: Low AQI and low pollutant levels support brief ventilation.

Air quality and outdoor metrics

US AQI

Air Quality Index

39

Good

PM2.5

Fine particulate matter

9.3µg/m³

Low

PM10

Coarse particulate matter

11.6µg/m³

Low

NO₂

Nitrogen dioxide

10µg/m³

Low

O₃

Ozone

41µg/m³

Low

UV index

Sun exposure level

1

Low

Temperature

Air temperature

16°C

Comfortable

Feels like

Apparent temperature

16°C

Comfortable

Wind

Wind speed

5km/h

Light

Humidity

Relative humidity

78%

Humid

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Disclaimer

This information is a general estimate only and is not medical advice.

Location

San Jose, United States

Coordinates: 37.3382, -121.8863 · America/Los_Angeles

Interpret AQI for outdoor activity

Calculic's European AQI calculator assesses the value using your population group and planned activity intensity.

Interpret AQI in Calculic

This page's European AQI value, city and timestamp are passed to the calculator through the link.

What affects air quality in San Jose

The Bay Area Air District's 2026 network plan describes how northwesterly winds can bring ozone and its precursors into the Santa Clara Valley around San Jose - Jackson, while light winds and winter inversions can increase particle concentrations.

This is the plan's site-area meteorological context, not a forecast, a source ranking or a claim that all San Jose neighborhoods have the same conditions.

Local monitoring and context

City air quality FAQ

How should I read the AQI for San Jose?

US AQI condenses air quality into one value. On this page, it helps you quickly judge whether conditions look good, moderate or more polluted than usual.

Is the air quality good for going outside?

Check the outdoor and running cards first. They combine AQI, particles, ozone, weather and other factors that can affect outdoor comfort.

Should I ventilate right now?

The ventilation card considers AQI and pollutants such as particles, nitrogen dioxide and ozone. If values are elevated, a shorter opening or a later moment may be better.

Why can air quality change during the day?

Weather, emissions, ozone formation, particles and air flow can shift local conditions, so the next hours can differ from the current reading.

Sources and methodology

Current data

This page uses US AQI.

Current and hourly air-quality values are CAMS-based model estimates, not measurements from a local monitoring station. They may not reflect street-level conditions.

Displayed state
Current model estimate
Data time
3 Sept 2026, 08:00 am
Data source
Open-Meteo

Evergreen city statements

Each local statement is linked to a checked primary-authority source. A source check is editorial provenance and does not describe current-data freshness.

Local sources support the background claims below; they are not the source of the current data shown above unless explicitly stated otherwise.

Authoritative sources for local statements

2026 Annual Air Monitoring Network Plan — San Jose - Jackson, Tables 4.45–4.46

Bay Area Air District

Scope
San Jose
Source checked
31 Aug 2026

Printed pages 98–99 identify Jackson as an NCore site, describe ozone transport and winter inversions, and list agency-operated ozone, CO, NO2, SO2 and particulate monitors. The discontinued NOy and NATTS programs are not claimed as active.

Applicability: Official local or regional background only; not current conditions, citywide uniformity, regulatory attainment or this site's current-data provenance.

Based on this source: The Bay Area Air District's 2026 network plan describes how northwesterly winds can bring ozone and its precursors into the Santa Clara Valley around San Jose - Jackson, while light winds and winter inversions can increase particle concentrations.

The Bay Area Air District's 2026 network plan identifies San Jose - Jackson as an NCore site and lists ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide and particulate monitoring there.