421
CXUS56 KSEW 011132
CLMSEA
CLIMATE REPORT
NATIONAL WEATHER SERVICE SEATTLE
332 AM PST THU JAN 01 2026
...............................
...THE SEATTLE-TACOMA WA AIRPORT CLIMATE SUMMARY FOR THE MONTH OF DECEMBER 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
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TEMPERATURE (F)
RECORD
HIGH 66 12/10/2014
LOW 6 12/30/1968
HIGHEST 57 12/10 MM MM 59 12/20
12/15
LOWEST 30 12/28 MM MM 28 12/03
AVG. MAXIMUM 49.2 47.0 2.2 49.1
AVG. MINIMUM 41.2 37.1 4.1 38.8
MEAN 45.2 42.0 3.2 43.9
DAYS MAX >= 90 0 0.0 0.0 MM
DAYS MAX <= 32 0 0.5 -0.5 MM
DAYS MIN <= 32 2 7.2 -5.2 MM
DAYS MIN <= 0 0 0.0 0.0 MM
PRECIPITATION (INCHES)
RECORD
MAXIMUM 11.85 1979
MINIMUM 1.37 1978
TOTALS 7.37 5.72 1.65 5.50
DAILY AVG. 0.25 0.18 0.07 0.18
DAYS >= .01 20 18.4 1.6 MM
DAYS >= .10 14 12.1 1.9 MM
DAYS >= .50 3 3.6 -0.6 MM
DAYS >= 1.00 2 1.0 1.0 MM
GREATEST
24 HR. TOTAL 1.66 12/09 TO 12/10
SNOWFALL (INCHES)
RECORDS
TOTAL 22.1 1968
TOTALS 0.0 1.7 -1.7 0.0
SINCE 7/1 0.0 1.9 -1.9 MM
SNOWDEPTH AVG. 0 0
DAYS >= 1.0 0 MM
GREATEST
SNOW DEPTH 0 0
24 HR TOTAL MM MM
DEGREE DAYS
HEATING TOTAL 606 711 -105 646
SINCE 7/1 1520 1770 -250 MM
COOLING TOTAL 0 0 0 0
SINCE 1/1 328 263 65 MM
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WIND (MPH)
AVERAGE WIND SPEED 9.3
HIGHEST WIND SPEED/DIRECTION 37/210 DATE 12/17
HIGHEST GUST SPEED/DIRECTION 53/200 DATE 12/06
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.85
NUMBER OF DAYS FAIR 0
NUMBER OF DAYS PC 8
NUMBER OF DAYS CLOUDY 23
AVERAGE RH (PERCENT) 86
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 0 MIXED PRECIP 0
HEAVY RAIN 1 RAIN 8
LIGHT RAIN 24 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 0
HEAVY SNOW 0 SNOW 0
LIGHT SNOW 0 SLEET 0
FOG 24 FOG W/VIS <= 1/4 MILE 5
HAZE 1
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
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