159
CXUS56 KSEW 011050
CLMSEA

CLIMATE REPORT
NATIONAL WEATHER SERVICE SEATTLE
350 AM PDT WED OCT 01 2025

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

...THE SEATTLE-TACOMA WA AIRPORT CLIMATE SUMMARY FOR THE MONTH OF SEPTEMBER 2025...

CLIMATE NORMAL PERIOD 1991 TO 2020
CLIMATE RECORD PERIOD 1945 TO 2025

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           91   09/16         MM      MM       90  09/05
LOWEST            50   09/25         MM      MM       47  09/21
                       09/26
AVG. MAXIMUM    73.1               71.6     1.5     70.5
AVG. MINIMUM    55.2               53.6     1.6     54.7
MEAN            64.2               62.6     1.6     62.6
DAYS MAX >= 90     1                0.2     0.8        1
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          0.76               1.61   -0.85     0.62
DAILY AVG.      0.03               0.05   -0.03     0.02
DAYS >= .01        6                8.3    -2.3        8
DAYS >= .10        2                4.2    -2.2        2
DAYS >= .50        0                0.9    -0.9        0
DAYS >= 1.00       0                0.2    -0.2        0
GREATEST
 24 HR. TOTAL   0.43   09/21 TO 09/21

DEGREE DAYS
HEATING TOTAL     51                102     -51      106
 SINCE 7/1        75                158     -83       MM
COOLING TOTAL     34                 30       4       42
 SINCE 1/1       328                263      65       MM
................................................................

WIND (MPH)
AVERAGE WIND SPEED              6.3
HIGHEST WIND SPEED/DIRECTION    25/210    DATE  09/14
HIGHEST GUST SPEED/DIRECTION    36/210    DATE  09/30

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.54
NUMBER OF DAYS FAIR           10
NUMBER OF DAYS PC             11
NUMBER OF DAYS CLOUDY          9

AVERAGE RH (PERCENT)     71

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              1     MIXED PRECIP               0
HEAVY RAIN                1     RAIN                       1
LIGHT RAIN                7     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                0     SLEET                      0
FOG                      11     FOG W/VIS <= 1/4 MILE      3
HAZE                      5

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

$$