El Dorado County, California Air Quality
The nearest monitor to El Dorado County, at Colfax, 32 miles away, measured an index of 43 at Fri, 8:00 PM PDT, which is Good for fine particles (PM2.5). El Dorado County AQMD forecasts Good for Placerville today and Good tomorrow.
- Measured now
- 43 · Good
- Today
- 42 · Good
- Tomorrow
- 38 · Good
- Pollutant
- PM2.5
Fine particles on the map
Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over El Dorado County, California. Open it for the live map, where it pans and zooms.























Open the live map with the particulate forecast
Map layer from NOAA National Air Quality Forecast Capability. Boundaries from the Iowa Environmental Mesonet.
Alerts in force
An Air Quality Alert is issued by the National Weather Service on behalf of a state or local agency when pollution is expected to reach a level that harms health. An Air Stagnation Advisory means the air will not move enough to clear what is already in it.
None are in force near El Dorado County right now. All California warnings.
Now
Good
- Nearest monitor
- Colfax, 32 miles away (site 060610004)
- Index measured
- 43 · Good
- Measured at
- Fri, 8:00 PM PDT
- Fine particles
- 8 µg/m³
- Ozone
- 29 ppb
- Reporting area
- Placerville, CA, 15 miles away
- Reported by
- El Dorado County AQMD
Measured, not modeled. AirNow observations are preliminary until the operating agency certifies them, which happens months later.
Today and tomorrow
El Dorado County AQMD's own forecast for Placerville, written by a forecaster rather than read off a model.
| Day | Category | Index | Pollutant |
|---|---|---|---|
| Today | Good | 42 | Ozone |
| Tomorrow | Good | 38 | Ozone |
| Sunday, September 27 | Good | 32 | Ozone |
| Monday, September 28 | Good | 41 | Ozone |
| Tuesday, September 29 | Good | 49 | Ozone |
| Wednesday, September 30 | Moderate | 61 | Ozone |
The forecaster’s discussion
Written by El Dorado County AQMD for Placerville and filed with AirNow.
Friday, light to moderate southerly to southwesterly winds will aid dispersion in the Sacramento region as a trough of low pressure moves onshore over the Pacific Northwest. Furthermore, slightly cooler temperatures will hinder ozone formation, leading to high-Good ozone levels. Saturday and Sunday, as the next trough of low pressure deepens offshore, atmospheric mixing will gradually improve. In addition, as temperatures continue to cool, ozone development will decrease. Therefore, despite light onshore winds limiting dispersion each day, ozone levels will be Good on both days.
Hour by hour
NOAA’s National Air Quality Forecast Capability, bias-corrected against monitors, for this town’s own coordinate. The worst hour ahead is an index of 34, Good, around Sun, 11:00 AM PDT, from the run issued Fri, 8:00 PM PDT. This is a model, not a measurement.
| Hour | Index | Category | PM2.5 | Ozone |
|---|---|---|---|---|
| Fri, 9:00 PM PDT | 29 | Good | 1 | 31.1 |
| Fri, 10:00 PM PDT | 29 | Good | 1.5 | 31.5 |
| Fri, 11:00 PM PDT | 29 | Good | 1.3 | 31.7 |
| Sat, 12:00 AM PDT | 29 | Good | 1.4 | 31.5 |
| Sat, 1:00 AM PDT | 28 | Good | 1.1 | 30.8 |
| Sat, 2:00 AM PDT | 27 | Good | 1.4 | 29.6 |
| Sat, 3:00 AM PDT | 26 | Good | 1.8 | 28.5 |
| Sat, 4:00 AM PDT | 25 | Good | 1 | 27.8 |
| Sat, 5:00 AM PDT | 25 | Good | 0.9 | 27.4 |
| Sat, 6:00 AM PDT | 24 | Good | 1.1 | 26.9 |
| Sat, 7:00 AM PDT | 24 | Good | 1.1 | 26.4 |
| Sat, 8:00 AM PDT | 23 | Good | 1.1 | 26 |
| Sat, 9:00 AM PDT | 23 | Good | 2.4 | 25.8 |
| Sat, 10:00 AM PDT | 24 | Good | 4.3 | 26.5 |
| Sat, 11:00 AM PDT | 25 | Good | 5.3 | 27.7 |
| Sat, 12:00 PM PDT | 26 | Good | 4.5 | 28.7 |
| Sat, 1:00 PM PDT | 27 | Good | 3.5 | 29.7 |
| Sat, 2:00 PM PDT | 28 | Good | 2.6 | 30.8 |
| Sat, 3:00 PM PDT | 29 | Good | 2.3 | 32 |
| Sat, 4:00 PM PDT | 31 | Good | 2.4 | 33.4 |
| Sat, 5:00 PM PDT | 32 | Good | 3 | 35.1 |
| Sat, 6:00 PM PDT | 33 | Good | 3.2 | 36.1 |
| Sat, 7:00 PM PDT | 33 | Good | 2.9 | 36.4 |
| Sat, 8:00 PM PDT | 33 | Good | 2.2 | 36.3 |
| Sat, 9:00 PM PDT | 33 | Good | 2.5 | 36.1 |
| Sat, 10:00 PM PDT | 32 | Good | 2.9 | 35.7 |
| Sat, 11:00 PM PDT | 32 | Good | 3 | 35.3 |
| Sun, 12:00 AM PDT | 31 | Good | 3.2 | 34.7 |
| Sun, 1:00 AM PDT | 31 | Good | 3 | 34 |
| Sun, 2:00 AM PDT | 31 | Good | 3.5 | 33.2 |
| Sun, 3:00 AM PDT | 30 | Good | 3.8 | 32.6 |
| Sun, 4:00 AM PDT | 30 | Good | 3.2 | 32.4 |
| Sun, 5:00 AM PDT | 30 | Good | 3.4 | 32.3 |
| Sun, 6:00 AM PDT | 29 | Good | 3.5 | 32 |
| Sun, 7:00 AM PDT | 29 | Good | 4.6 | 31.6 |
| Sun, 8:00 AM PDT | 28 | Good | 5.2 | 30.7 |
| Sun, 9:00 AM PDT | 29 | Good | 5.8 | 29.9 |
| Sun, 10:00 AM PDT | 32 | Good | 6.5 | 29.5 |
| Sun, 11:00 AM PDT | 34 | Good | 6.6 | 29.4 |
| Sun, 12:00 PM PDT | 32 | Good | 5.3 | 29.4 |
| Sun, 1:00 PM PDT | 27 | Good | 3.2 | 29.4 |
| Sun, 2:00 PM PDT | 27 | Good | 2 | 29.7 |
| Sun, 3:00 PM PDT | 28 | Good | 2.2 | 30.3 |
| Sun, 4:00 PM PDT | 29 | Good | 2.1 | 31.2 |
| Sun, 5:00 PM PDT | 30 | Good | 2.6 | 32.4 |
| Sun, 6:00 PM PDT | 31 | Good | 2.1 | 33.2 |
| Sun, 7:00 PM PDT | 31 | Good | 1.9 | 33.8 |
| Sun, 8:00 PM PDT | 31 | Good | 1.5 | 34.1 |
| Sun, 9:00 PM PDT | 31 | Good | 1.5 | 34.2 |
| Sun, 10:00 PM PDT | 31 | Good | 1.2 | 33.9 |
| Sun, 11:00 PM PDT | 31 | Good | 1.2 | 33 |
| Mon, 12:00 AM PDT | 29 | Good | 1 | 31.7 |
| Mon, 1:00 AM PDT | 28 | Good | 1.1 | 30.2 |
| Mon, 2:00 AM PDT | 26 | Good | 1.9 | 28.6 |
| Mon, 3:00 AM PDT | 24 | Good | 2.2 | 27 |
| Mon, 4:00 AM PDT | 23 | Good | 1.2 | 25.6 |
| Mon, 5:00 AM PDT | 22 | Good | 0.7 | 24.7 |
Fine particles in micrograms per cubic meter, ozone in parts per billion as an 8-hour average. The index for each hour is EPA’s: the ozone figure is already the 8-hour average the ozone index is defined on, and the particle figure is run through EPA’s NowCast, which is how an hourly PM2.5 concentration becomes an index.
Smoke
NOAA’s analysts have not drawn smoke over El Dorado County in satellite imagery today.
NOAA’s model forecasts near-surface smoke peaking at 4.9 µg/m³ around Sat, 7:00 AM PDT.
What this means
Good
Air quality is satisfactory, and air pollution poses little or no risk.
- Who is affected
- Nobody is expected to be affected.
- What to do
- It is a good day to be outside.
- Index range
- 0 to 50
Category descriptions are the Environmental Protection Agency’s own.
What these numbers are. An index beside a monitor’s name is a measurement, published hourly by AirNow and preliminary until the operating agency certifies it. A category for today or tomorrow is a state or local agency forecaster’s own forecast for a reporting area. An hourly index is NOAA’s air quality model on a five-kilometer grid, not a reading from any instrument. Where a town has no monitor within reach, only the model figures appear, and the page says so.
Nearby
The nearest towns with a page of their own, closest first.
Weather forecast for El Dorado CountyWarnings in El Dorado CountyLive radar over El Dorado CountyCalifornia air quality
Sources
Observations and daily forecasts from AirNow, the US Environmental Protection Agency’s program with NOAA, the National Park Service, NASA, tribal, state and local agencies. Hourly forecasts from NOAA’s National Air Quality Forecast Capability. Smoke analysis from NOAA’s Hazard Mapping System. Alerts from the National Weather Service. Index categories and breakpoints are EPA’s, as revised in 2024.