SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT DAILY AIR QUALITY FORECAST VALID: FRI., SEP. 18, 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 52 46 0.9 25 10 22 53 2 NW Coastal LA 45 40 0.3 25 8 12 44 3 SW Coastal LA 40 36 0.2 24 7 10 39 4 S Coastal LA 48 43 0.3 25 8 23 44 5 Southeast LA Co 49 44 0.6 27 9 22 50 6 W San Fernando Vly 65 57 0.3 26 9 15 58 7 E San Fernando Vly 63 56 0.6 27 12 18 56 8 W San Gabriel Vly 59 49 0.3 31 12 13 56 9 E San Gabriel Vly 72 59 0.4 36 11 19 64 10 Pomona Walnut Vly 71 57 0.4 36 11 21 58 11 S San Gabriel Vly 53 47 0.4 32 10 19 53 12 S Central LA Co 46 41 0.3 25 9 21 50 13 Santa Clarita Vly 75 65 0.3 29 9 16 84 15 San Gabriel Mts 67 58 0.3 36 11 23 61 Los Angeles County: Mojave Desert Air Basin 14 Antelope Vly 55 54 0.3 37 12 27 56 Orange County: South Coast Air Basin 16 N Orange Co 54 47 0.2 31 9 13 50 17 Central Orange Co 46 41 0.4 25 8 19 44 18 N Coastal Orange Co 42 40 0.3 24 5 21 37 19 Saddleback Vly 47 43 0.2 29 5 17 40 20 Central Coastal 42 40 0.2 22 5 16 37 21 Capistrano Vly 41 38 0.2 22 5 13 35 Riverside County: South Coast Air Basin 22 Norco/Corona 60 53 0.4 37 10 17 53 23 Metro Riverside Co 70 59 0.5 39 11 16 64 24 Perris Vly 66 58 0.4 36 10 20 61 25 Lake Elsinore 59 49 0.3 18 8 11 45 26 Temecula Vly 48 44 0.2 27 7 11 41 27 Anza Vly 54 51 0.2 31 5 11 47 28 Hemet/San Jacinto 62 55 0.3 35 9 19 51 29 Banning 72 62 0.3 34 8 14 74 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- 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 74 61 0.2 43 8 12 71 Riverside County: Mojave Desert Air Basin 31 E Riverside Co 49 47 0.2 30 5 11 44 San Bernardino County: South Coast Air Basin 32 NW San Bernardino Vly 65 54 0.4 35 12 19 56 33 SW San Bernardino Vly 64 54 0.4 37 11 20 55 34 C San Bernardino Vly 79 64 0.3 42 10 24 80 35 E San Bernardino Vly 78 66 0.4 39 9 22 87 36 W San Bernardino Mtns 70 59 0.3 35 10 23 64 37 C San Bernardino Mtns 75 63 0.3 40 5 25 77 38 Big Bear Lake 67 63 0.3 37 5 24 77 San Bernardino County: Mojave Desert Air Basin 39 Phelan 63 57 0.3 33 6 26 58 40 Hesperia 71 64 0.3 29 7 27 80 41 Trona 48 47 0.2 33 5 8 44 42 Victorville 69 63 0.3 32 8 27 77 43 Yucca Vly 64 60 0.2 36 6 20 67 44 Barstow 58 52 0.2 33 6 42 48 45 Twentynine Palms 53 52 0.2 35 7 18 48 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- AIR QUALITY FORECAST -------------------------------------------------------------------------------- ON FRI., SEP. 18, 2026, THE SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT PREDICTS THE AIR QUALITY WILL BE ... GOOD in the following area(s): Coastal Area AQI: 44 PM2.5 Inland Orange County AQI: 44 PM2.5 Northern Mojave Desert AQI: 48 Ozone Temecula/Anza Area AQI: 47 Ozone MODERATE in the following area(s): Antelope Valley AQI: 56 PM2.5 Banning Pass Area AQI: 74 Ozone Big Bear Lake AQI: 77 Ozone Central Mojave Desert AQI: 67 Ozone Coachella Valley/Low Desert AQI: 71 Ozone Hemet/Elsinore Area AQI: 61 Ozone Metropolitan Area AQI: 53 PM2.5 Riverside Valley AQI: 64 Ozone San Bernardino Mountains AQI: 77 Ozone San Bernardino Valley AQI: 87 Ozone San Fernando/Santa Clarita Valleys AQI: 84 Ozone San Gabriel Mountains AQI: 61 Ozone San Gabriel Valley AQI: 64 Ozone Victor Valley AQI: 80 Ozone ------------------------------------------------------------------------ ------------------------------------------------------------------------ WEATHER FORECAST ------------------------------------------------------------------------ Onshore pressure gradients and warming temperatures on Friday. Inversion Base: 3141 FT | Breaking Temperature: 85 DEG F Inversion Breaking: NO | Maximum Mixing HEIGHT: 3535 FT ------------------------------------------------------------------------ ------------------------------------------------------------------------ AIR QUALITY FORECAST RULE IMPLICATIONS ------------------------------------------------------------------------ Area 40 - South Coast Air Basin: BURN 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 FRIDAY, SEPTEMBER 18, 2026 IN THE SOUTH COAST AIR BASIN.