Loyalton, California Air Quality
The nearest monitor to Loyalton, at Portola, 15 miles away, measured an index of 20 at Fri, 3:00 AM PDT, which is Good for fine particles (PM2.5). Northern Sierra AQMD forecasts Good for Portola today and Good tomorrow.
- Measured now
- 20 · Good
- Today
- 22 · Good
- Tomorrow
- 22 · Good
- Pollutant
- PM2.5
Fine particles on the map
Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Loyalton, 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 Loyalton right now. All California warnings.
Now
Good
- Nearest monitor
- Portola, 15 miles away (site 060631010)
- Index measured
- 20 · Good
- Measured at
- Fri, 3:00 AM PDT
- Fine particles
- 4.1 µg/m³
- Reporting area
- Portola, CA, 15 miles away
- Reported by
- Northern Sierra AQMD
- Area index
- 20 · Good
Measured, not modeled. AirNow observations are preliminary until the operating agency certifies them, which happens months later.
Today and tomorrow
Northern Sierra AQMD's own forecast for Portola, written by a forecaster rather than read off a model.
| Day | Category | Index | Pollutant |
|---|---|---|---|
| Today | Good | 22 | PM2.5 |
| Tomorrow | Good | 22 | PM2.5 |
| Sunday, September 27 | Good | 28 | PM2.5 |
| Monday, September 28 | Good | 39 | PM2.5 |
| Tuesday, September 29 | Good | 39 | PM2.5 |
The forecaster’s discussion
Written by Northern Sierra AQMD for Portola and filed with AirNow.
Thursday, September 24 and Friday, September 25: As an upper-level trough of low pressure passes to the north, gusty southwesterly surface winds will develop in Portola each afternoon, effectively dispersing pollutants and keeping AQI levels Good on both days. Saturday and Sunday, moderate southwesterly to southerly surface winds will redevelop each afternoon as the next trough of low pressure approaches the northern California coast. These winds will effectively disperse pollutants, yielding continued Good AQI levels on both days. Monday and Tuesday, calm to light winds will inhibit pollutant dispersion each morning and evening. Furthermore, morning temperature inversions will trap pollutants near the ground. However, low pollutant carryover from the day to day will keep AQI levels Good in the Portola region 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 52, Moderate, around Fri, 5:00 AM PDT, from the run issued Thu, 11:00 PM PDT. This is a model, not a measurement.
| Hour | Index | Category | PM2.5 | Ozone |
|---|---|---|---|---|
| Fri, 5:00 AM PDT | 52 | Moderate | 8.5 | |
| Fri, 6:00 AM PDT | 51 | Moderate | 8.7 | |
| Fri, 7:00 AM PDT | 46 | Good | 6.9 | 44.5 |
| Fri, 8:00 AM PDT | 38 | Good | 5.3 | 41.3 |
| Fri, 9:00 AM PDT | 35 | Good | 6 | 38.8 |
| Fri, 10:00 AM PDT | 33 | Good | 4.4 | 36.3 |
| Fri, 11:00 AM PDT | 31 | Good | 4.6 | 33.8 |
| Fri, 12:00 PM PDT | 29 | Good | 4.8 | 31.7 |
| Fri, 1:00 PM PDT | 28 | Good | 4.5 | 30.3 |
| Fri, 2:00 PM PDT | 28 | Good | 2.9 | 30.2 |
| Fri, 3:00 PM PDT | 28 | Good | 2.9 | 30.5 |
| Fri, 4:00 PM PDT | 29 | Good | 2 | 31.2 |
| Fri, 5:00 PM PDT | 29 | Good | 1.6 | 31.6 |
| Fri, 6:00 PM PDT | 30 | Good | 3 | 32.6 |
| Fri, 7:00 PM PDT | 31 | Good | 2.3 | 34.3 |
| Fri, 8:00 PM PDT | 32 | Good | 2.9 | 35.4 |
| Fri, 9:00 PM PDT | 32 | Good | 2.7 | 35.9 |
| Fri, 10:00 PM PDT | 32 | Good | 2.5 | 35.8 |
| Fri, 11:00 PM PDT | 32 | Good | 2.7 | 35.3 |
| Sat, 12:00 AM PDT | 31 | Good | 3.3 | 34.4 |
| Sat, 1:00 AM PDT | 31 | Good | 3.8 | 33.2 |
| Sat, 2:00 AM PDT | 29 | Good | 3.6 | 31.7 |
| Sat, 3:00 AM PDT | 27 | Good | 3 | 29.6 |
| Sat, 4:00 AM PDT | 25 | Good | 3.2 | 27.5 |
| Sat, 5:00 AM PDT | 23 | Good | 1.8 | 25.4 |
| Sat, 6:00 AM PDT | 21 | Good | 2.7 | 23.4 |
| Sat, 7:00 AM PDT | 19 | Good | 2.6 | 21.6 |
| Sat, 8:00 AM PDT | 19 | Good | 2.1 | 20.5 |
| Sat, 9:00 AM PDT | 18 | Good | 3.4 | 19.9 |
| Sat, 10:00 AM PDT | 19 | Good | 4.2 | 20.3 |
| Sat, 11:00 AM PDT | 23 | Good | 5 | 21.3 |
| Sat, 12:00 PM PDT | 28 | Good | 6 | 23.1 |
| Sat, 1:00 PM PDT | 27 | Good | 4.6 | 25.6 |
| Sat, 2:00 PM PDT | 26 | Good | 2.7 | 28.4 |
| Sat, 3:00 PM PDT | 29 | Good | 3.1 | 31.5 |
| Sat, 4:00 PM PDT | 31 | Good | 2.5 | 34.5 |
| Sat, 5:00 PM PDT | 33 | Good | 1.5 | 37 |
| Sat, 6:00 PM PDT | 35 | Good | 1.8 | 38.6 |
| Sat, 7:00 PM PDT | 36 | Good | 2.4 | 39.9 |
| Sat, 8:00 PM PDT | 37 | Good | 3.4 | 40.4 |
| Sat, 9:00 PM PDT | 37 | Good | 4.5 | 40.3 |
| Sat, 10:00 PM PDT | 36 | Good | 3.9 | 39.9 |
| Sat, 11:00 PM PDT | 35 | Good | 4.3 | 38.7 |
| Sun, 12:00 AM PDT | 34 | Good | 3.5 | 37.1 |
| Sun, 1:00 AM PDT | 32 | Good | 4.2 | 35.5 |
| Sun, 2:00 AM PDT | 31 | Good | 3.5 | 33.5 |
| Sun, 3:00 AM PDT | 29 | Good | 3 | 31.3 |
| Sun, 4:00 AM PDT | 27 | Good | 3.7 | 29.4 |
| Sun, 5:00 AM PDT | 25 | Good | 3.1 | 27.7 |
| Sun, 6:00 AM PDT | 23 | Good | 4.1 | 25.3 |
| Sun, 7:00 AM PDT | 21 | Good | 4.3 | 23.9 |
| Sun, 8:00 AM PDT | 24 | Good | 5.2 | 23.1 |
| Sun, 9:00 AM PDT | 28 | Good | 5.6 | 22.9 |
| Sun, 10:00 AM PDT | 29 | Good | 5.5 | 23.3 |
| Sun, 11:00 AM PDT | 31 | Good | 6 | 24 |
| Sun, 12:00 PM PDT | 31 | Good | 5.5 | 25.2 |
| Sun, 1:00 PM PDT | 27 | Good | 4.3 | 26.6 |
| Sun, 2:00 PM PDT | 27 | Good | 3.5 | 29.1 |
| Sun, 3:00 PM PDT | 29 | Good | 3.7 | 31.3 |
| Sun, 4:00 PM PDT | 31 | Good | 2.8 | 33.6 |
| Sun, 5:00 PM PDT | 32 | Good | 1.8 | 35.2 |
| Sun, 6:00 PM PDT | 33 | Good | 1.8 | 36.4 |
| Sun, 7:00 PM PDT | 34 | Good | 2.1 | 37.3 |
| Sun, 8:00 PM PDT | 34 | Good | 1.9 | 37.6 |
| Sun, 9:00 PM PDT | 34 | Good | 2 | 37.9 |
| Sun, 10:00 PM PDT | 34 | Good | 1.6 | 37.8 |
| Sun, 11:00 PM PDT | 34 | Good | 1.5 | 37.3 |
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 Loyalton in satellite imagery today.
NOAA’s model forecasts near-surface smoke peaking at 1.4 µg/m³ around Fri, 5:00 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 LoyaltonWarnings in Sierra CountyLive radar over LoyaltonCalifornia 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.