Climatological Report (Monthly)
Issued by NWS Boise, ID
Issued by NWS Boise, ID
000 CXUS55 KBOI 011732 CLMBOI CLIMATE REPORT NATIONAL WEATHER SERVICE BOISE ID 1126 AM MDT SAT JUL 01 2023 JUNE WAS WARM AND STORMY, WITH TEMPERATURES SLIGHTLY ABOVE NORMAL. PRECIPITATION WAS ABOVE NORMAL AT THE AIRPORT, WITH JUST UNDER AN INCH OF RAIN. HEAVIER SHOWERS WERE CONCENTRATED FROM THE AIRPORT NORTH ACROSS EASTERN PORTIONS OF BOISE AND THE NEARBY FOOTHILLS. BECAUSE OF THE SCATTERED NATURE OF CONVECTIVE SHOWERS, MANY AREAS OF THE TREASURE VALLEY HAD MUCH LESS RAIN. FOR EXAMPLE, ONE LOCATION 3 MILES WEST-SOUTHWEST OF THE AIRPORT MEASURED UNDER A QUARTER INCH FOR THE MONTH. BETWEEN THE 1ST AND THE 6TH, TWO UPPER-LEVEL TROUGHS, ONE OVER THE GULF OF ALASKA AND THE OTHER OVER THE PACIFIC BETWEEN CALIFORNIA AND HAWAII, WERE DRIFTING SLOWLY EASTWARD. DURING THAT PERIOD, AN UPPER-LEVEL RIDGE OVER THE WESTERN STATES WAS RESPONSIBLE FOR RAISING TEMPERATURES FROM A FEW DEGREES ABOVE NORMAL FROM THE 1ST TROUGH THE 3RD TO AROUND 10 DEGREES ABOVE NORMAL FROM THE 4TH THROUGH THE 6TH. BY THE MORNING OF THE 6TH, THE NORTHERN TROUGH HAD MOVED INLAND OVER WESTERN CANADA WITH LITTLE EFFECT ON OUR AREA, WHILE THE SOUTHERN TROUGH, CARRYING ABUNDANT MOISTURE, WAS OVER SOUTHERN CALIFORNIA. BY THE AFTERNOON OF THE 6TH, THE SOUTHERN TROUGH HAD CHANGED COURSE AND WAS HEADING TOWARDS IDAHO. SURFACE HEATING HAD RAISED TEMPERATURES INTO THE LOWER 90`S IN THE BOISE AREA, RESULTING IN AN UNSTABLE ATMOSPHERE WHICH TRIGGERED STRONG THUNDERSTORMS, FUELED BY MOISTURE COMING UP FROM THE SOUTH. ONE OF THESE STORMS UNLEASHED TORRENTIAL RAIN OVER THE AIRPORT AND EAST BOISE, RESULTING IN FLOODING OF MANY STREETS IN THE DOWNTOWN AND NORTH END AREAS. WATER OVERWHELMED STORM DRAINS AND FLOWED OVER SIDEWALKS AND LAWNS. WATER UP TO TWO FEET DEEP LEFT SEVERAL VEHICLES STRANDED DOWNTOWN. THE CONNECTOR WAS FLOODED, AS WERE SOME APARTMENTS AND SEVERAL BUILDINGS ON THE BSU CAMPUS. RAINFALL RATES OVER AN INCH AN HOUR, WITH LOCALIZED TOTALS UP TO 1.85 INCHES, OCCURRED BETWEEN 6 PM AND 10 PM MDT. THE TROUGH HUNG OVER THE WESTERN REGION, RESULTING IN DAILY SHOWERS AND THUNDERSTORMS WITH STRONG GUSTY WINDS. THE STORMS BUILT OVER THE MOUNTAINS AND MOVED OVER THE VALLEY DURING THE AFTERNOONS AND EVENINGS FROM THE 7TH THROUGH THE 13TH, BUT RAINFALL TOTALS WERE LIGHT AT THE AIRPORT. ON THE 7TH, THUNDERSTORM OUTFLOW WINDS UP TO 58 MPH WERE REPORTED AROUND BOISE. ON THE 11TH, HAIL RANGING FROM HALF AN INCH TO AN INCH FELL WITH THUNDERSTORMS IN THE TREASURE VALLEY. ON THE 13TH, A LARGE TREE WAS BLOWN DOWN THREE MILES NORTHWEST OF GARDEN CITY. ALSO ON THE 13TH, STREET FLOODING FROM THUNDERSTORMS WAS REPORTED IN EAGLE, WITH ABOUT 8 INCHES OF STANDING WATER. ON THE 14TH, TEMPERATURES TOOK A DIVE AND HUMIDITIES PLUMMETED FOLLOWING A COLD FRONT. HIGHS WERE NEAR NORMAL ON THE 14TH AND A FEW DEGREES BELOW NORMAL ON THE 15TH AND 16TH. ON THE 18TH, A WINTRY TROUGH FROM THE GULF OF ALASKA INVADED THE PACIFIC NORTHWEST. ONLY LIGHT RAIN FELL AT THE AIRPORT, AND SNOW FELL ON THE MOUNTAINS ABOVE 6000 FEET. TEMPERATURES AVERAGED 10-15 DEGREES BELOW NORMAL FROM THE 19TH THROUGH THE 21ST. THE HIGH ON THE 19TH WAS ONLY 62, WITH BLUSTERY NORTHWEST WINDS GUSTING AS HIGH AS 46 MPH. ON THE 21ST, THE FIRST DAY OF SUMMER, THE HIGH WAS A PLEASANT 73. NO MEASURABLE RAIN FELL FOR THE REST OF THE MONTH. THE TROUGH GRADUALLY WEAKENED AND RELOCATED OFFSHORE. A WEAK RIDGE BUILT OVER THE AREA ON THE 24TH AND 25TH, RAISING TEMPERATURES A FEW DEGREES ABOVE NORMAL. THE TROUGH SHIFTED BACK INLAND ON THE 25TH, AND TEMPERATURES WERE A FEW DEGREES BELOW NORMAL THROUGH THE 28TH. ON THE 29TH, AN UPPER-LEVEL RIDGE BEGAN TO BUILD IN FROM THE WEST, AND ON THE 30TH THE TEMPERATURE MAXED OUT AT 96 DEGREES. ................................... ...THE BOISE ID CLIMATE SUMMARY FOR THE MONTH OF JUNE 2023... CLIMATE NORMAL PERIOD 1991 TO 2020 CLIMATE RECORD PERIOD 1875 TO 2023 WEATHER OBSERVED NORMAL DEPART LAST YEAR`S VALUE DATE(S) VALUE FROM VALUE NORMAL .............................................................. TEMPERATURE (F) HIGHEST 96 06/30 LOWEST 41 06/20 AVG. MAXIMUM 81.7 81.4 0.3 AVG. MINIMUM 55.8 54.1 1.7 MEAN 68.8 67.8 0.9 DAYS MAX >= 90 3 DAYS MAX <= 32 0 DAYS MIN <= 32 0 DAYS MIN <= 0 0 PRECIPITATION (INCHES) RECORD MAXIMUM 3.41 1941 TOTALS 0.97 0.75 0.22 DAYS >= .01 8 DAYS >= .10 2 DAYS >= .50 1 DAYS >= 1.00 0 GREATEST 24 HR. TOTAL 0.56 06/06 TO 06/06 DEGREE DAYS HEATING TOTAL 30 61 -31 65 SINCE 7/1 5461 5320 141 COOLING TOTAL 151 143 8 143 SINCE 1/1 246 188 58 .............................................................. WIND (MPH) AVERAGE WIND SPEED 7.2 HIGHEST WIND SPEED/DIRECTION 36/300 DATE 06/19 36/280 06/26 HIGHEST GUST SPEED/DIRECTION 51/070 DATE 06/07 AVERAGE RH (PERCENT) 50 - INDICATES NEGATIVE NUMBERS. R INDICATES RECORD WAS SET OR TIED. MM INDICATES DATA IS MISSING. T INDICATES TRACE AMOUNT. $$