SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT DAILY AIR QUALITY FORECAST VALID: SUN., SEP. 20, 2026 -------------------------------------------------------------------------------- SRA AREA 1-HR 8-HR 8-HR 24-HR 24-HR 1-HR MAX NUMBER OZONE OZONE CO PM10 PM2.5 NO2 AQI PPB PPB PPM UG/M3 UG/M3 PPB -------------------------------------------------------------------------------- Los Angeles County: South Coast Air Basin 1 Central LA Co 64 56 0.7 28 13 10 58 2 NW Coastal LA 48 44 0.3 28 7 7 41 3 SW Coastal LA 41 38 0.1 27 8 9 44 4 S Coastal LA 52 47 0.2 26 9 12 50 5 Southeast LA Co 58 53 0.5 29 11 13 55 6 W San Fernando Vly 69 64 0.3 28 10 6 80 7 E San Fernando Vly 69 62 0.5 30 14 11 74 8 W San Gabriel Vly 73 61 0.4 35 14 9 71 9 E San Gabriel Vly 77 63 0.4 41 12 10 77 10 Pomona Walnut Vly 74 62 0.4 41 12 15 74 11 S San Gabriel Vly 65 57 0.3 35 12 13 58 12 S Central LA Co 57 52 0.3 27 11 11 55 13 Santa Clarita Vly 78 69 0.2 31 14 12 97 15 San Gabriel Mts 72 65 0.4 41 14 15 84 Los Angeles County: Mojave Desert Air Basin 14 Antelope Vly 73 67 0.2 37 12 17 90 Orange County: South Coast Air Basin 16 N Orange Co 59 54 0.2 38 11 8 55 17 Central Orange Co 52 47 0.3 20 11 6 55 18 N Coastal Orange Co 48 45 0.2 24 6 10 42 19 Saddleback Vly 51 48 0.2 38 5 7 44 20 Central Coastal 48 45 0.2 26 5 7 42 21 Capistrano Vly 46 43 0.3 30 6 5 40 Riverside County: South Coast Air Basin 22 Norco/Corona 66 60 0.3 54 12 9 67 23 Metro Riverside Co 75 66 0.4 62 14 8 87 24 Perris Vly 61 58 0.3 41 14 15 61 25 Lake Elsinore 53 50 0.3 29 11 4 55 26 Temecula Vly 48 45 0.3 35 8 6 44 27 Anza Vly 53 51 0.3 40 6 8 47 28 Hemet/San Jacinto 59 55 0.3 38 11 17 55 29 Banning 68 60 0.3 36 10 13 67 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- SRA AREA 1-HR 8-HR 8-HR 24-HR 24-HR 1-HR MAX NUMBER OZONE OZONE CO PM10 PM2.5 NO2 AQI PPB PPB PPM UG/M3 UG/M3 PPB -------------------------------------------------------------------------------- Riverside County: Salton Sea Air Basin 30 Coachella Vly 64 58 0.2 47 7 10 61 Riverside County: Mojave Desert Air Basin 31 E Riverside Co 57 49 0.2 31 5 9 45 San Bernardino County: South Coast Air Basin 32 NW San Bernardino Vly 72 62 0.4 35 14 13 74 33 SW San Bernardino Vly 70 61 0.4 54 13 16 71 34 C San Bernardino Vly 79 71 0.4 44 14 21 101 35 E San Bernardino Vly 77 69 0.4 42 14 21 97 36 W San Bernardino Mtns 71 62 0.3 40 12 26 74 37 C San Bernardino Mtns 78 71 0.3 43 9 30 101 38 Big Bear Lake 66 61 0.3 40 6 27 71 San Bernardino County: Mojave Desert Air Basin 39 Phelan 59 55 0.3 40 7 35 51 40 Hesperia 70 64 0.3 42 9 38 80 41 Trona 57 52 0.2 26 5 19 48 42 Victorville 71 67 0.3 41 11 40 90 43 Yucca Vly 57 54 0.2 32 5 21 50 44 Barstow 63 58 0.2 42 9 50 61 45 Twentynine Palms 54 51 0.2 31 5 19 47 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- AIR QUALITY FORECAST -------------------------------------------------------------------------------- ON SUN., SEP. 20, 2026, THE SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT PREDICTS THE AIR QUALITY WILL BE ... GOOD in the following area(s): Central Mojave Desert AQI: 50 Ozone Coastal Area AQI: 50 PM2.5 Temecula/Anza Area AQI: 47 Ozone MODERATE in the following area(s): Antelope Valley AQI: 90 Ozone Banning Pass Area AQI: 67 Ozone Big Bear Lake AQI: 71 Ozone Coachella Valley/Low Desert AQI: 61 Ozone Hemet/Elsinore Area AQI: 61 Ozone Inland Orange County AQI: 55 PM2.5 Metropolitan Area AQI: 58 PM2.5 Northern Mojave Desert AQI: 61 Ozone Riverside Valley AQI: 87 Ozone San Fernando/Santa Clarita Valleys AQI: 97 Ozone San Gabriel Mountains AQI: 84 Ozone San Gabriel Valley AQI: 77 Ozone Victor Valley AQI: 90 Ozone UNHEALTHY FOR SENSITIVE GROUPS in the following area(s): San Bernardino Mountains AQI: 101 Ozone San Bernardino Valley AQI: 101 Ozone ------------------------------------------------------------------------ ------------------------------------------------------------------------ WEATHER FORECAST ------------------------------------------------------------------------ Light pressure gradients and persistent ventilation on Sunday. Decreasing temperatures. Inversion Base: 2284 FT | Breaking Temperature: 82 DEG F Inversion Breaking: NO | Maximum Mixing HEIGHT: 3102 FT ------------------------------------------------------------------------ ------------------------------------------------------------------------ AIR QUALITY FORECAST RULE IMPLICATIONS ------------------------------------------------------------------------ Area 40 - South Coast Air Basin: MARGINAL-BURN Burning is prohibited in the following source/receptor areas: 34, 37 Area 53 - Mojave Desert Air Basin: BURN Area 55 - Salton Sea Air Basin: BURN Beach Fire Ring Wood Burning: Allowed in All Areas Residential Wood Burning: Allowed in All Areas Coachella Valley Rule 403.1 Wind Forecast: Winds Below 25 MPH ------------------------------------------------------------------------ ATTENTION ALL SCHOOLS AND INDUSTRIES THIS IS THE SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT NO AIR POLLUTION OR HEALTH ADVISIORY EPISODES ARE PREDICTED FOR SUNDAY, SEPTEMBER 20, 2026 IN THE SOUTH COAST AIR BASIN.