Climatological Report (Monthly)
Issued by NWS Boise, ID

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
000
CXUS55 KBOI 020503 CCA
CLMBOI

CLIMATE REPORT...CORRECTED TO ADD NARRATIVE
NATIONAL WEATHER SERVICE BOISE ID
1104 PM MDT THU JUN 01 2023

THE AVERAGE TEMPERATURE OF 65.0 IS 5.1 DEGREES ABOVE NORMAL. THE
LOWS OF 57 ON THE 1ST AND 60 ON THE 20TH WERE RECORDS FOR THE DATES.
THE HIGH OF 92 ON THE 21ST WAS ALSO A RECORD FOR THE DATE.

THE TOTAL PRECIPITATION OF 1.43 INCH IS .02 INCH BELOW NORMAL.

AN UPPER LEVEL TROUGH CENTERED JUST OFFSHORE NEAR THE WASHINGTON
COAST ON THE 1ST PUT US UNDER SOUTHERLY FLOW AS IT DRIFTED SOUTH
ALONG THE COAST, KEEPING TEMPERATURES 10-15 DEGREES ABOVE NORMAL
FROM THE 1ST THROUGH THE 3RD.

BY THE 4TH THE TROUGH WAS CENTERED OVER THE CALIFORNIA COAST, POISED
TO LIFT NORTH AS ANOTHER TROUGH DEEPENED OFF THE WASHINGTON-OREGON
COAST.

AS THE CALIFORNIA TROUGH MOVED NORTH, IT DROPPED TEMPERATURES TO A
FEW DEGREES BELOW NORMAL AND GENERATED SHOWERS FROM THE 5TH THROUGH
THE 9TH AS A SERIES OF SECONDARY TROUGHS ROTATED THROUGH THE MAIN
TROUGH. PRECIPITATION FOR THAT PERIOD TOTALED 1.00 INCH. THE .41
INCH ON THE 7TH WAS BY FAR THE HIGHEST DAILY TOTAL. THE HIGH OF 59
THAT DAY WAS THE COOLEST MAX OF THE MONTH.

AN UPPER LEVEL RIDGE BOUGHT DRY AND WARMER WEATHER FROM THE 10TH
THROUGH THE 12TH.

ON THE 13TH A WEAK TROUGH BEGAN TO IMPINGE ON THE RIDGE FROM THE
SOUTHEAST. BY THE 14TH THE TROUGH HAD REPLACED A PORTION OF THE
RIDGE SOUTH OF THE CANADIAN BORDER.

SUFFICIENT MOISTURE AND INSTABILITY RESULTED IN MEASURABLE RAIN ON
THE 14TH AND 15TH, WITH A QUARTER INCH FALLING IN A THUNDERSTORM ON
THE 15TH. THE STORM ALSO PRODUCED SMALL HAIL AND A WIND GUST OF 44
MPH FROM THE SOUTH.

BY THE 19TH THE RIDGE OVER THE INTERMOUNTAIN REGION HAD RECOVERED,
BRINGING BOISE THE FIRST 90 DEGREE HIGHS OF THE SEASON FROM THE 19TH
THROUGH THE 21ST. THE 92 ON THE 20TH WAS THE MONTH`S HIGH. SMOKE
FROM WILDFIRES IN WESTERN CANADA ACCOMPANIED THE HEAD.

DURING THE NIGHT OF THE 21ST A PACIFIC COLD FRONT PASSED BOISE, WITH
LIGHT PRECIPITATION BUT MAJOR COOLING ON THE 22ND AS AN UPPER LEVEL
TROUGH FOLLOWED THE FRONT INLAND. A GUST OF 51 MPH ACCOMPANIED THE
FRONTAL PASSAGE. THE HIGH OF 91 AHEAD OF THE FRONT ON THE 21ST WAS
FOLLOWED BY A HIGH OF ONLY 74 ON THE 22ND.

TROUGHINESS PERSISTED WEST OF THE ROCKIES FOR THE REST OF THE MONTH,
WITH NEARLY DAILY SHOWERS IN THE MOIST UNSTABLE AIR. THE BOISE
AIRPORT MISSED OUT ON THE HEAVIER SHOWERS, WITH ONLY .01 INCH ON THE
24TH AND .08 INCH ON THE 30TH.

ON THE 30TH A ROGUE THUNDERSTORM DEVELOPED OVER THE OWYHEES AND
ROLLED ACROSS THE VALLEY. PRECIPITATION AMOUNTS WERE QUITE VARIABLE.
THE AIRPORT WAS ON THE EDGE OF THE STORM AND RECEIVED LITTLE
PRECIPITATION. BUT THE STORM`S ABUNDANT MOISTURE AND SLOW MOVEMENT
GUARANTEED THAT LOCATIONS UNDER ITS CORE WOULD BE DRENCHED WITH
HEAVY RAIN, RESULTING IN LOCAL URBAN FLOODING. IN FACT THERE WERE A
COUPLE OF REPORTS OF AROUND HALF AN INCH OF STORM TOTAL RAINFALL IN
TOWN, AND SOCIAL MEDIA POSTS OF STREET AND SIDEWALK FLOODING.

ON THE 31ST SHOWER AND THUNDERSTORMS DEVELOPED ALONG A PACIFIC COLD
FRONT. ONLY .05 INCH OF RAIN WAS MEASURED AT THE AIRPORT. THE
THUNDERSTORMS GAINED STRENGTH AS THE FRONT CONTINUED EASTWARD, WITH
SOME STORMS REACHING SEVERE INTENSITY IN SOUTH CENTRAL IDAHO.
...................................

...THE BOISE ID CLIMATE SUMMARY FOR THE MONTH OF MAY 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           92   05/20
LOWEST            41   05/10
AVG. MAXIMUM    77.5               72.3     5.2
AVG. MINIMUM    52.5               47.5     5.0
MEAN            65.0               59.9     5.1
DAYS MAX >= 90     3
DAYS MAX <= 32     0
DAYS MIN <= 32     0
DAYS MIN <= 0      0

PRECIPITATION (INCHES)
RECORD
 MAXIMUM        4.90   1890
TOTALS          1.05               1.45   -0.40
DAYS >= .01        8
DAYS >= .10        5
DAYS >= .50        0
DAYS >= 1.00       0
GREATEST
 24 HR. TOTAL   0.39   05/08 TO 05/09

SNOWFALL (INCHES)
TOTALS             T
SINCE 7/1       31.2
GREATEST
 SNOW DEPTH        0
 24 HR TOTAL      MM

DEGREE DAYS
HEATING TOTAL     81                200    -119      300
 SINCE 7/1      5431               5258     173
COOLING TOTAL     86                 42      44       14
 SINCE 1/1        95                 45      50
..............................................................

WIND (MPH)
AVERAGE WIND SPEED              7.3
HIGHEST WIND SPEED/DIRECTION    35/260    DATE  05/21
HIGHEST GUST SPEED/DIRECTION    51/270    DATE  05/21

AVERAGE RH (PERCENT)     49


-  INDICATES NEGATIVE NUMBERS.
R  INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T  INDICATES TRACE AMOUNT.

$$


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.