SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT DAILY AIR QUALITY FORECAST VALID: SUN., DEC. 21, 2025 -------------------------------------------------------------------------------- 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 40 35 0.9 39 27 32 84 2 NW Coastal LA 42 39 0.6 35 25 22 81 3 SW Coastal LA 41 38 0.8 37 21 29 73 4 S Coastal LA 42 36 1.0 38 24 24 79 5 Southeast LA Co 44 37 1.1 38 36 32 102 6 W San Fernando Vly 46 40 0.8 31 21 25 73 7 E San Fernando Vly 46 39 0.9 38 22 29 75 8 W San Gabriel Vly 51 43 0.9 37 22 28 75 9 E San Gabriel Vly 50 42 0.6 33 24 26 79 10 Pomona Walnut Vly 48 39 0.9 38 34 36 97 11 S San Gabriel Vly 44 36 0.6 38 36 32 102 12 S Central LA Co 45 40 1.1 38 34 31 97 13 Santa Clarita Vly 50 39 0.5 31 18 18 68 15 San Gabriel Mts 46 38 0.8 36 15 29 62 Los Angeles County: Mojave Desert Air Basin 14 Antelope Vly 42 36 0.7 26 14 19 60 Orange County: South Coast Air Basin 16 N Orange Co 47 38 0.5 40 35 26 99 17 Central Orange Co 43 36 0.9 39 33 26 96 18 N Coastal Orange Co 38 34 0.9 36 17 24 66 19 Saddleback Vly 53 44 0.5 40 12 27 56 20 Central Coastal 44 38 0.6 31 17 22 66 21 Capistrano Vly 46 41 0.6 27 18 20 68 Riverside County: South Coast Air Basin 22 Norco/Corona 52 43 0.9 47 36 30 102 23 Metro Riverside Co 54 44 0.9 51 40 31 112 24 Perris Vly 50 43 0.9 46 22 33 75 25 Lake Elsinore 54 44 0.6 25 16 20 64 26 Temecula Vly 46 40 0.5 24 5 20 37 27 Anza Vly 41 37 0.4 25 5 22 34 28 Hemet/San Jacinto 47 42 0.9 38 8 32 44 29 Banning 45 43 0.8 32 10 25 53 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- 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 50 43 0.3 35 14 26 60 Riverside County: Mojave Desert Air Basin 31 E Riverside Co 38 34 0.3 24 7 17 39 San Bernardino County: South Coast Air Basin 32 NW San Bernardino Vly 55 45 1.0 34 25 32 81 33 SW San Bernardino Vly 50 40 0.9 45 37 34 105 34 C San Bernardino Vly 46 40 1.1 49 23 39 77 35 E San Bernardino Vly 45 40 1.0 48 15 36 62 36 W San Bernardino Mtns 46 40 1.0 28 16 35 64 37 C San Bernardino Mtns 49 46 1.1 44 9 38 50 38 Big Bear Lake 42 38 1.0 39 13 34 58 San Bernardino County: Mojave Desert Air Basin 39 Phelan 42 38 0.8 25 5 34 35 40 Hesperia 42 39 0.9 20 9 37 50 41 Trona 32 29 0.4 19 5 10 28 42 Victorville 44 40 0.8 23 11 36 55 43 Yucca Vly 44 41 0.5 26 6 26 38 44 Barstow 40 29 0.6 24 8 33 44 45 Twentynine Palms 40 37 0.4 26 6 24 34 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- AIR QUALITY FORECAST -------------------------------------------------------------------------------- ON SUN., DEC. 21, 2025, THE SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT PREDICTS THE AIR QUALITY WILL BE ... GOOD in the following area(s): Central Mojave Desert AQI: 38 Ozone Northern Mojave Desert AQI: 44 PM2.5 Temecula/Anza Area AQI: 37 Ozone MODERATE in the following area(s): Antelope Valley AQI: 60 PM2.5 Banning Pass Area AQI: 53 PM2.5 Big Bear Lake AQI: 58 PM2.5 Coachella Valley/Low Desert AQI: 60 PM2.5 Coastal Area AQI: 81 PM2.5 Hemet/Elsinore Area AQI: 75 PM2.5 Inland Orange County AQI: 96 PM2.5 San Bernardino Mountains AQI: 64 PM2.5 San Fernando/Santa Clarita Valleys AQI: 75 PM2.5 San Gabriel Mountains AQI: 62 PM2.5 Victor Valley AQI: 55 PM2.5 UNHEALTHY FOR SENSITIVE GROUPS in the following area(s): Metropolitan Area AQI: 102 PM2.5 Riverside Valley AQI: 112 PM2.5 San Bernardino Valley AQI: 105 PM2.5 San Gabriel Valley AQI: 102 PM2.5 ------------------------------------------------------------------------ ------------------------------------------------------------------------ WEATHER FORECAST ------------------------------------------------------------------------ Morning low clouds and patchy fog are expected, clearing inland by late morning but lingering near the coast. Warm and dry, with temperatures 10–15° above normal inland and near normal at the coast. Inversion Base: 486 FT | Breaking Temperature: 68 DEG F Inversion Breaking: YES | Maximum Mixing HEIGHT: 1698 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: Prohibited in South Coast Air Basin Below 3000 ft 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, DECEMBER 21, 2025 IN THE SOUTH COAST AIR BASIN.