SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT DAILY AIR QUALITY FORECAST VALID: WED., SEP. 23, 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 67 56 0.7 31 12 26 56 2 NW Coastal LA 53 47 0.5 29 11 21 55 3 SW Coastal LA 44 39 0.3 30 10 22 53 4 S Coastal LA 53 46 0.3 28 9 30 50 5 Southeast LA Co 65 52 0.5 31 13 26 58 6 W San Fernando Vly 72 66 0.5 28 9 19 87 7 E San Fernando Vly 67 59 0.6 32 10 26 64 8 W San Gabriel Vly 76 64 0.4 34 10 26 80 9 E San Gabriel Vly 85 70 0.6 38 10 28 100 10 Pomona Walnut Vly 85 69 0.6 38 13 33 97 11 S San Gabriel Vly 72 58 0.4 35 13 26 61 12 S Central LA Co 60 46 0.2 30 12 19 56 13 Santa Clarita Vly 80 68 0.3 31 9 27 93 15 San Gabriel Mts 74 64 0.5 38 8 32 80 Los Angeles County: Mojave Desert Air Basin 14 Antelope Vly 61 57 0.4 35 10 35 58 Orange County: South Coast Air Basin 16 N Orange Co 73 56 0.3 38 13 17 58 17 Central Orange Co 63 49 0.5 27 12 17 56 18 N Coastal Orange Co 52 45 0.3 28 5 27 42 19 Saddleback Vly 59 51 0.2 38 6 23 47 20 Central Coastal 55 47 0.3 30 6 23 44 21 Capistrano Vly 58 51 0.4 33 7 23 47 Riverside County: South Coast Air Basin 22 Norco/Corona 81 66 0.5 49 11 26 87 23 Metro Riverside Co 93 71 0.6 53 12 29 101 24 Perris Vly 71 60 0.5 42 11 35 67 25 Lake Elsinore 65 56 0.4 33 10 24 54 26 Temecula Vly 53 49 0.4 33 7 22 45 27 Anza Vly 45 43 0.3 33 4 20 40 28 Hemet/San Jacinto 61 55 0.5 35 6 37 51 29 Banning 59 55 0.4 31 5 39 51 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- 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 56 52 0.2 36 4 17 48 Riverside County: Mojave Desert Air Basin 31 E Riverside Co 40 38 0.2 25 4 18 35 San Bernardino County: South Coast Air Basin 32 NW San Bernardino Vly 79 66 0.7 36 11 28 87 33 SW San Bernardino Vly 81 66 0.6 48 13 38 87 34 C San Bernardino Vly 86 72 0.6 38 9 46 105 35 E San Bernardino Vly 86 71 0.5 45 8 37 101 36 W San Bernardino Mtns 78 64 0.5 35 7 37 80 37 C San Bernardino Mtns 63 58 0.5 36 5 38 61 38 Big Bear Lake 57 56 0.5 34 4 37 54 San Bernardino County: Mojave Desert Air Basin 39 Phelan 60 56 0.5 32 5 38 54 40 Hesperia 60 56 0.5 27 6 40 54 41 Trona 53 49 0.3 16 4 51 48 42 Victorville 60 55 0.5 30 7 40 51 43 Yucca Vly 50 47 0.3 27 4 27 44 44 Barstow 56 53 0.4 31 4 46 49 45 Twentynine Palms 44 42 0.3 27 4 25 39 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- AIR QUALITY FORECAST -------------------------------------------------------------------------------- ON WED., SEP. 23, 2026, THE SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT PREDICTS THE AIR QUALITY WILL BE ... GOOD in the following area(s): Central Mojave Desert AQI: 44 Ozone Coachella Valley/Low Desert AQI: 48 Ozone Northern Mojave Desert AQI: 49 Ozone Temecula/Anza Area AQI: 45 Ozone MODERATE in the following area(s): Antelope Valley AQI: 58 Ozone Banning Pass Area AQI: 51 Ozone Big Bear Lake AQI: 54 Ozone Coastal Area AQI: 55 PM2.5 Hemet/Elsinore Area AQI: 67 Ozone Inland Orange County AQI: 56 PM2.5 Metropolitan Area AQI: 58 PM2.5 San Bernardino Mountains AQI: 80 Ozone San Fernando/Santa Clarita Valleys AQI: 93 Ozone San Gabriel Mountains AQI: 80 Ozone San Gabriel Valley AQI: 100 Ozone Victor Valley AQI: 54 Ozone UNHEALTHY FOR SENSITIVE GROUPS in the following area(s): Riverside Valley AQI: 101 Ozone San Bernardino Valley AQI: 105 Ozone ------------------------------------------------------------------------ ------------------------------------------------------------------------ WEATHER FORECAST ------------------------------------------------------------------------ Temperatures are expected to rise multiple degrees on Wednesday and the marine layer will shrink. LA County is expected to experience offshore winds throughout the morning, turning to weak onshore flow in the afternoon. Inversion Base: 1481 FT | Breaking Temperature: 82 DEG F Inversion Breaking: YES | Maximum Mixing HEIGHT: 2857 FT ------------------------------------------------------------------------ ------------------------------------------------------------------------ AIR QUALITY FORECAST RULE IMPLICATIONS ------------------------------------------------------------------------ Area 40 - South Coast Air Basin: MARGINAL-BURN Burning is prohibited in the following source/receptor areas: 23, 34, 35 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 WEDNESDAY, SEPTEMBER 23, 2026 IN THE SOUTH COAST AIR BASIN.