SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT DAILY AIR QUALITY FORECAST VALID: SAT., DEC. 20, 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 41 34 0.7 52 31 34 92 2 NW Coastal LA 40 35 0.6 46 26 27 82 3 SW Coastal LA 36 33 0.8 49 28 29 86 4 S Coastal LA 42 36 0.8 47 32 33 94 5 Southeast LA Co 46 37 1.1 50 36 35 102 6 W San Fernando Vly 49 40 1.0 41 28 31 86 7 E San Fernando Vly 48 39 0.9 50 29 36 88 8 W San Gabriel Vly 49 40 0.8 49 31 38 92 9 E San Gabriel Vly 48 38 0.7 41 33 36 96 10 Pomona Walnut Vly 49 38 0.9 47 39 36 110 11 S San Gabriel Vly 47 36 0.8 50 35 34 99 12 S Central LA Co 48 39 1.1 49 43 31 119 13 Santa Clarita Vly 50 37 0.5 40 13 23 58 15 San Gabriel Mts 48 39 0.9 47 20 35 71 Los Angeles County: Mojave Desert Air Basin 14 Antelope Vly 38 35 0.7 31 19 19 69 Orange County: South Coast Air Basin 16 N Orange Co 46 37 0.6 50 36 30 102 17 Central Orange Co 44 36 0.7 44 32 30 94 18 N Coastal Orange Co 44 39 0.7 43 17 31 66 19 Saddleback Vly 50 43 0.4 50 10 31 53 20 Central Coastal 45 40 0.5 38 10 26 53 21 Capistrano Vly 45 41 0.6 34 9 22 50 Riverside County: South Coast Air Basin 22 Norco/Corona 53 43 0.8 62 38 34 107 23 Metro Riverside Co 52 42 0.9 68 43 35 119 24 Perris Vly 47 42 1.0 57 23 36 77 25 Lake Elsinore 52 44 0.6 33 19 20 69 26 Temecula Vly 45 41 0.5 35 6 20 38 27 Anza Vly 44 41 0.4 38 6 21 38 28 Hemet/San Jacinto 47 43 0.9 48 11 35 55 29 Banning 48 45 0.9 42 11 32 55 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- 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 47 44 0.3 47 19 22 69 Riverside County: Mojave Desert Air Basin 31 E Riverside Co 37 34 0.3 35 11 18 55 San Bernardino County: South Coast Air Basin 32 NW San Bernardino Vly 58 47 0.9 45 27 35 84 33 SW San Bernardino Vly 51 40 0.9 60 44 38 122 34 C San Bernardino Vly 47 39 1.2 61 26 40 82 35 E San Bernardino Vly 45 40 1.1 59 14 38 60 36 W San Bernardino Mtns 50 43 1.0 39 22 37 75 37 C San Bernardino Mtns 52 48 1.1 56 11 38 55 38 Big Bear Lake 44 41 1.0 50 10 36 53 San Bernardino County: Mojave Desert Air Basin 39 Phelan 44 42 0.9 35 7 33 39 40 Hesperia 45 41 1.0 35 10 37 53 41 Trona 31 28 0.4 25 6 13 33 42 Victorville 45 41 0.9 35 11 34 55 43 Yucca Vly 52 43 0.5 36 8 25 44 44 Barstow 41 29 0.7 28 11 32 55 45 Twentynine Palms 43 37 0.4 36 9 23 50 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- AIR QUALITY FORECAST -------------------------------------------------------------------------------- ON SAT., DEC. 20, 2025, THE SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT PREDICTS THE AIR QUALITY WILL BE ... GOOD in the following area(s): Central Mojave Desert AQI: 50 PM2.5 Temecula/Anza Area AQI: 38 Ozone MODERATE in the following area(s): Antelope Valley AQI: 69 PM2.5 Banning Pass Area AQI: 55 PM2.5 Big Bear Lake AQI: 53 PM2.5 Coachella Valley/Low Desert AQI: 69 PM2.5 Coastal Area AQI: 94 PM2.5 Hemet/Elsinore Area AQI: 77 PM2.5 Inland Orange County AQI: 94 PM2.5 Northern Mojave Desert AQI: 55 PM2.5 San Bernardino Mountains AQI: 75 PM2.5 San Fernando/Santa Clarita Valleys AQI: 88 PM2.5 San Gabriel Mountains AQI: 71 PM2.5 Victor Valley AQI: 55 PM2.5 UNHEALTHY FOR SENSITIVE GROUPS in the following area(s): Metropolitan Area AQI: 119 PM2.5 Riverside Valley AQI: 119 PM2.5 San Bernardino Valley AQI: 122 PM2.5 San Gabriel Valley AQI: 110 PM2.5 ------------------------------------------------------------------------ ------------------------------------------------------------------------ WEATHER FORECAST ------------------------------------------------------------------------ Night and morning coastal low clouds and fog are expected, spreading at times into the far western valleys. Onshore flow brings a few degrees of cooling, though temperatures remain above normal inland. Dry conditions continue. Inversion Base: 486 FT | Breaking Temperature: 69 DEG F Inversion Breaking: NO | Maximum Mixing HEIGHT: 1776 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 SATURDAY, DECEMBER 20, 2025 IN THE SOUTH COAST AIR BASIN.