SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT DAILY AIR QUALITY FORECAST VALID: THU., AUG. 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 69 57 0.5 24 14 30 60 2 NW Coastal LA 52 41 0.3 26 12 17 56 3 SW Coastal LA 47 37 0.1 27 11 17 55 4 S Coastal LA 51 43 0.2 32 10 25 53 5 Southeast LA Co 64 54 0.4 33 12 26 56 6 W San Fernando Vly 74 65 0.3 27 10 21 84 7 E San Fernando Vly 66 58 0.5 27 13 25 61 8 W San Gabriel Vly 84 70 0.5 31 13 20 100 9 E San Gabriel Vly 102 82 0.4 36 12 27 140 10 Pomona Walnut Vly 98 80 0.5 43 13 38 133 11 S San Gabriel Vly 74 62 0.4 35 13 24 74 12 S Central LA Co 61 51 0.3 28 11 22 55 13 Santa Clarita Vly 89 79 0.3 30 11 24 129 15 San Gabriel Mts 81 71 0.4 37 11 31 101 Los Angeles County: Mojave Desert Air Basin 14 Antelope Vly 66 63 0.3 38 13 31 77 Orange County: South Coast Air Basin 16 N Orange Co 71 59 0.2 45 11 14 64 17 Central Orange Co 55 47 0.3 34 11 10 55 18 N Coastal Orange Co 50 43 0.2 33 7 21 40 19 Saddleback Vly 58 52 0.2 45 6 20 48 20 Central Coastal 55 49 0.3 33 7 19 45 21 Capistrano Vly 55 50 0.3 34 8 21 46 Riverside County: South Coast Air Basin 22 Norco/Corona 91 77 0.3 57 12 24 122 23 Metro Riverside Co 104 88 0.3 63 14 24 156 24 Perris Vly 88 79 0.3 42 13 29 129 25 Lake Elsinore 70 63 0.3 34 10 22 77 26 Temecula Vly 57 52 0.3 34 10 20 53 27 Anza Vly 62 57 0.3 35 6 18 58 28 Hemet/San Jacinto 76 70 0.3 35 10 29 100 29 Banning 90 81 0.3 34 7 27 136 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- 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 84 67 0.3 44 8 16 90 Riverside County: Mojave Desert Air Basin 31 E Riverside Co 44 42 0.2 33 6 13 39 San Bernardino County: South Coast Air Basin 32 NW San Bernardino Vly 94 82 0.5 39 13 36 140 33 SW San Bernardino Vly 95 79 0.5 57 13 38 129 34 C San Bernardino Vly 102 83 0.4 33 12 43 143 35 E San Bernardino Vly 105 85 0.3 40 11 31 150 36 W San Bernardino Mtns 86 76 0.4 37 9 37 118 37 C San Bernardino Mtns 96 82 0.3 33 7 34 140 38 Big Bear Lake 83 74 0.3 35 7 31 112 San Bernardino County: Mojave Desert Air Basin 39 Phelan 70 68 0.3 33 6 30 93 40 Hesperia 68 63 0.3 26 8 33 77 41 Trona 57 51 0.2 25 6 18 47 42 Victorville 66 64 0.3 31 9 29 80 43 Yucca Vly 76 67 0.3 38 9 21 90 44 Barstow 65 60 0.3 32 10 34 67 45 Twentynine Palms 62 58 0.3 37 7 19 61 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- AIR QUALITY FORECAST -------------------------------------------------------------------------------- ON THU., AUG. 20, 2026, THE SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT PREDICTS THE AIR QUALITY WILL BE ... MODERATE in the following area(s): Antelope Valley AQI: 77 Ozone Central Mojave Desert AQI: 90 Ozone Coachella Valley/Low Desert AQI: 90 Ozone Coastal Area AQI: 56 PM2.5 Inland Orange County AQI: 55 PM2.5 Metropolitan Area AQI: 64 Ozone Northern Mojave Desert AQI: 67 Ozone Temecula/Anza Area AQI: 58 Ozone Victor Valley AQI: 93 Ozone UNHEALTHY FOR SENSITIVE GROUPS in the following area(s): Banning Pass Area AQI: 136 Ozone Big Bear Lake AQI: 112 Ozone Hemet/Elsinore Area AQI: 129 Ozone San Bernardino Mountains AQI: 140 Ozone San Bernardino Valley AQI: 150 Ozone San Fernando/Santa Clarita Valleys AQI: 129 Ozone San Gabriel Mountains AQI: 101 Ozone San Gabriel Valley AQI: 140 Ozone UNHEALTHY in the following area(s): Riverside Valley AQI: 156 Ozone ------------------------------------------------------------------------ ------------------------------------------------------------------------ WEATHER FORECAST ------------------------------------------------------------------------ High temperatures of around 4 to 8 degrees above average are expected. Night and morning low clouds will continue for the coastal waters into coastal areas. Greater monsoonal moisture on Thursday will bring a chance of afternoon showers and thunderstorms for the mountains and deserts. Inversion Base: 811 FT | Breaking Temperature: 89 DEG F Inversion Breaking: YES | Maximum Mixing HEIGHT: 1802 FT ------------------------------------------------------------------------ ------------------------------------------------------------------------ AIR QUALITY FORECAST RULE IMPLICATIONS ------------------------------------------------------------------------ Area 40 - South Coast Air Basin: NO-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 THURSDAY, AUGUST 20, 2026 IN THE SOUTH COAST AIR BASIN.