186
CXUS56 KSEW 011031
CLMSEA

CLIMATE REPORT
NATIONAL WEATHER SERVICE SEATTLE
331 AM PDT TUE OCT 01 2024

...................................

...THE SEATTLE-TACOMA WA AIRPORT CLIMATE SUMMARY FOR THE MONTH OF SEPTEMBER 2024...

CLIMATE NORMAL PERIOD 1991 TO 2020
CLIMATE RECORD PERIOD 1945 TO 2024

WEATHER         OBSERVED          NORMAL  DEPART   LAST YEAR`S
                VALUE   DATE(S)   VALUE   FROM     VALUE DATE(S)
                                          NORMAL
................................................................
TEMPERATURE (F)
RECORD
 HIGH             98   09/02/1988
 LOW              35   09/27/1972
HIGHEST           90   09/05         MM      MM       87  09/02
LOWEST            47   09/21         MM      MM       46  09/29
AVG. MAXIMUM    70.5               71.6    -1.1     70.6
AVG. MINIMUM    54.7               53.6     1.1     53.4
MEAN            62.6               62.6    -0.0     62.0
DAYS MAX >= 90     1                0.2     0.8        0
DAYS MAX <= 32     0                0.0     0.0        0
DAYS MIN <= 32     0                0.0     0.0        0
DAYS MIN <= 0      0                0.0     0.0        0

PRECIPITATION (INCHES)
RECORD
 MAXIMUM        6.17   2013
 MINIMUM           T   1991
TOTALS          0.62               1.61   -0.99     3.44
DAILY AVG.      0.02               0.05   -0.03     0.11
DAYS >= .01        8                8.3    -0.3       11
DAYS >= .10        2                4.2    -2.2        8
DAYS >= .50        0                0.9    -0.9        3
DAYS >= 1.00       0                0.2    -0.2        0
GREATEST
 24 HR. TOTAL   0.24   09/11 TO 09/11

DEGREE DAYS
HEATING TOTAL    106                102       4      108
 SINCE 7/1       144                158     -14       MM
COOLING TOTAL     42                 30      12       26
 SINCE 1/1       315                263      52       MM
................................................................

WIND (MPH)
AVERAGE WIND SPEED              6.2
HIGHEST WIND SPEED/DIRECTION    20/220    DATE  09/25
HIGHEST GUST SPEED/DIRECTION    29/200    DATE  09/25

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.63
NUMBER OF DAYS FAIR            4
NUMBER OF DAYS PC             15
NUMBER OF DAYS CLOUDY         11

AVERAGE RH (PERCENT)     73

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              0     MIXED PRECIP               0
HEAVY RAIN                0     RAIN                       1
LIGHT RAIN               15     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                0     SLEET                      0
FOG                      16     FOG W/VIS <= 1/4 MILE      2
HAZE                      4

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

$$