


Climatological Report (Monthly)
Issued by NWS
Issued by NWS
620 CXUS56 KSGX 010940 CLMONT CLIMATE REPORT NATIONAL WEATHER SERVICE SAN DIEGO, CA 240 AM PDT WED OCT 01 2025 ................................... ...THE ONTARIO INTL AIRPORT CA CLIMATE SUMMARY FOR THE MONTH OF SEPTEMBER 2025... CLIMATE NORMAL PERIOD: 1991 TO 2020 CLIMATE RECORD PERIOD: 1998 TO 2025 WEATHER OBSERVED NORMAL DEPART LAST YEAR`S VALUE DATE(S) VALUE FROM VALUE DATE(S) NORMAL ................................................................ TEMPERATURE (F) RECORD HIGH 118 09/05/2020 LOW 51 09/27/2013 HIGHEST 102 09/02 91 11 114 09/06 LOWEST 61 09/12 62 -1 55 09/17 AVG. MAXIMUM 89.6 91.3 -1.7 90.9 AVG. MINIMUM 66.3 63.8 2.5 64.3 MEAN 77.9 77.6 0.3 77.6 DAYS MAX >= 90 15 17.5 -2.5 13 DAYS MAX <= 32 0 0.0 0.0 0 DAYS MAX >= 45 30 30 DAYS MAX >= 120 0 0 DAYS MIN <= 32 0 0.0 0.0 0 PRECIPITATION (INCHES) RECORD MAXIMUM 3.54 1963 MINIMUM 0.00 2020 TOTALS 0.12 0.10 0.02 T DAILY AVG. 0.00 0.00 -0.00 T DAYS >= .01 2 0.7 1.3 0 DAYS >= .10 0 0.3 -0.3 0 DAYS >= .50 0 0.0 0.0 0 DAYS >= 1.00 0 0.0 0.0 0 DAYS >= %-5.2F 0 0 DAYS >= %-5.2F 0 0 GREATEST 24 HR. TOTAL 0.09 09/18 TO 09/18 T 09/20 TO 09/20 09/16 TO 09/16 09/20 TO 09/20 STORM TOTAL 0.09 0.00 (MM/DD(HH)) MM DEGREE DAYS HEATING TOTAL 0 1 -1 0 SINCE 7/1 0 0 0 MM COOLING TOTAL 400 378 22 386 SINCE 1/1 1789 1751 38 MM FREEZE DATES RECORD EARLIEST 11/30/2004 LATEST 02/14/2006 EARLIEST 02/24 LATEST 02/20 ................................................................ WIND (MPH) AVERAGE WIND SPEED 5.8 RESULTANT WIND SPEED/DIRECTION 5/240 HIGHEST WIND SPEED/DIRECTION 22/230 DATE 09/17 HIGHEST GUST SPEED/DIRECTION 30/260 DATE 09/03 SKY COVER POSSIBLE SUNSHINE (PERCENT) MM AVERAGE SKY COVER 0.33 NUMBER OF DAYS FAIR 17 NUMBER OF DAYS PC 10 NUMBER OF DAYS CLOUDY 3 AVERAGE RH (PERCENT) 56 WEATHER CONDITIONS. NUMBER OF DAYS WITH THUNDERSTORM 0 MIXED PRECIP 0 HEAVY RAIN 0 RAIN 0 LIGHT RAIN 2 FREEZING RAIN 0 LT FREEZING RAIN 0 HAIL 0 HEAVY SNOW 0 SNOW 0 LIGHT SNOW 0 SLEET 0 FOG 2 FOG W/VIS <= 1/4 MILE 0 HAZE 4 - INDICATES NEGATIVE NUMBERS. R INDICATES RECORD WAS SET OR TIED. MM INDICATES DATA IS MISSING. T INDICATES TRACE AMOUNT. $$