704  
CXUS55 KBOI 011753  
CLMBOI  
 
CLIMATE REPORT  
NATIONAL WEATHER SERVICE BOISE ID  
1147 AM MDT SUN SEP 1 2019  
 
TEMPERATURES AVERAGED SLIGHTLY ABOVE NORMAL.  
 
MEASURABLE RAIN FELL ON 3 DAYS, TOTALING .09 INCH. AUGUST IS  
NORMALLY THE DRIEST MONTH OF THE YEAR, AVERAGING .24 INCH.  
 
PRECIPITATION FOR JUNE, JULY, AND AUGUST TOTALED ONLY .14 INCH,  
MAKING THIS THE SECOND DRIEST SUMMER ON RECORD AT THE AIRPORT.  
 
A MASSIVE UPPER LEVEL HIGH PRESSURE RIDGE COVERING THE WEST KEPT THE  
FIRST WEEK OF AUGUST HOT. TEMPERATURES AT BOISE TOPPED OUT AT 100 ON  
THE 5TH AND 101 ON THE 6TH.  
 
SOUTHERLY FLOW ALOFT BROUGHT ENOUGH MONSOON MOISTURE FOR LIGHT  
SHOWERS ON THE 2ND AND AGAIN ON THE 8TH, PLUS ENOUGH CLOUD COVER ON  
THE 8TH TO PREVENT THE TEMPERATURE FROM REACHING 90.  
 
ON THE 9TH AND 10TH, A LOW PRESSURE TROUGH WHICH HAD RESIDED OFF THE  
WEST COAST SINCE LATE JULY MOVED INLAND. AS THE ASSOCIATED COLD  
FRONT INTERACTED WITH THE MONSOON MOISTURE, IT TRIGGERED  
THUNDERSTORMS WHICH PRODUCED LIGHT BUT MEASURABLE PRECIPITATION AND  
GUSTY OUTFLOW WINDS. A GUST OF 40 MPH WAS MEASURED AT THE AIRPORT ON  
THE 9TH.  
 
WITH A HIGH OF ONLY 78, THE 11TH WAS THE COOLEST DAY OF THE MONTH,  
THANKS TO THE NORTH PACIFIC AIR WHICH ACCOMPANIED THE TROUGH.  
 
FOLLOWING THE TROUGH, HIGHS WERE BACK IN THE 90S FROM THE 13TH  
THROUGH THE 15TH, AND DRY WESTERLY FLOW ALOFT BLOCKED MONSOON  
MOISTURE FROM INVADING SOUTHWEST IDAHO.  
 
ON THE 16TH AND 17TH, A WEAK COLD FRONT TRAILING SOUTH FROM A LOW  
PRESSURE SYSTEM OVER CANADA LOWERED TEMPERATURES A FEW DEGREES.  
 
THE HIGH PRESSURE RIDGE EXPANDED NORTH AGAIN, AND HIGHS WERE IN THE  
90S FROM THE 18TH THROUGH THE 21ST.  
 
ON THE 22ND AND 23RD, A PACIFIC COLD FRONT, FOLLOWED BY AN UPPER  
LEVEL LOW PRESSURE TROUGH FROM THE THE GULF OF ALASKA, BROUGHT A  
TRACE OF RAIN AND KEPT HIGHS FROM EXCEEDING THE 80S. A DRY COLD  
FRONT FOLLOWED ON THE 25TH, KEEPING TEMPERATURES BELOW NORMAL  
THROUGH THE 26TH.  
 
A WARMING TREND COMMENCED ON THE 27TH AS THE HIGH PRESSURE RIDGE  
REBUILT AND PERSISTED THROUGH THE END OF THE MONTH, WITH  
TEMPERATURES AROUND 10 DEGREES ABOVE NORMAL.  
 
THE RIDGE EVENTUALLY ENTRAINED MONSOON MOISTURE AS WELL AS MOISTURE  
FROM A FORMER TROPICAL DISTURBANCE WHICH ORIGINATED OFF THE WEST  
COAST OF MEXICO. ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPED OVER  
EASTERN OREGON AND THE WEST CENTRAL IDAHO MOUNTAINS, BUT NO  
MEASURABLE RAIN FELL AT THE BOISE AIRPORT.   
...............................
 
 
   
..THE BOISE ID CLIMATE SUMMARY FOR THE MONTH OF AUGUST 2019
 
 
CLIMATE NORMAL PERIOD 1981 TO 2010  
CLIMATE RECORD PERIOD 1875 TO 2019  
 
WEATHER OBSERVED NORMAL DEPART LAST YEAR'S  
VALUE DATE(S) VALUE FROM VALUE  
NORMAL    
.........................................................
 
 
TEMPERATURE (F)  
HIGHEST 101 08/06  
LOWEST 52 08/26  
AVG. MAXIMUM 91.9 89.7 2.2  
AVG. MINIMUM 61.9 59.6 2.3  
MEAN 76.9 74.7 2.2  
DAYS MAX >= 90 20  
DAYS MAX <= 32 0  
DAYS MIN <= 32 0  
DAYS MIN <= 0 0  
 
PRECIPITATION (INCHES)  
RECORD  
MAXIMUM 2.37 1968  
TOTALS 0.09 0.24 -0.15  
DAYS >= .01 3  
DAYS >= .10 0  
DAYS >= .50 0  
DAYS >= 1.00 0  
GREATEST  
24 HR. TOTAL 0.06 08/09 TO 08/09  
 
DEGREE_DAYS  
HEATING TOTAL 0 10 -10 5  
SINCE 7/1 0 18 -18  
COOLING TOTAL 377 309 68 362  
SINCE 1/1 901 834 67    
..........................................................
 
 
WIND (MPH)  
AVERAGE WIND SPEED 6.7  
RESULTANT WIND SPEED/DIRECTION 2/305  
HIGHEST WIND SPEED/DIRECTION 26/290 DATE 08/10  
HIGHEST GUST SPEED/DIRECTION 40/190 DATE 08/09  
 
SKY COVER  
POSSIBLE SUNSHINE (PERCENT) MM  
 
AVERAGE RH (PERCENT) 36  
 
 
- INDICATES NEGATIVE NUMBERS.  
R INDICATES RECORD WAS SET OR TIED.  
MM INDICATES DATA IS MISSING.  
T INDICATES TRACE AMOUNT.  
 

 
 
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