Climatological Report (Monthly)
Issued by NWS

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
000
CXUS56 KSEW 011044
CLMSEA


CLIMATE REPORT
NATIONAL WEATHER SERVICE SEATTLE WA
344 AM PDT SUN OCT 1 2017

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

...THE SEATTLE-TACOMA WA AIRPORT CLIMATE SUMMARY FOR THE MONTH OF SEPTEMBER 2017...

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1945 TO 2017

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   09/03        MM      MM       78  09/14
                        09/02
LOWEST             50   09/24        MM      MM       46  09/30
                        09/21
                        09/20
AVG. MAXIMUM     73.8              70.5     3.3     69.6
AVG. MINIMUM     55.6              52.1     3.5     52.9
MEAN             64.7              61.3     3.4     61.2
DAYS MAX >= 90      2               0.2     1.8        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           0.59              1.50   -0.91     1.05
DAILY AVG.       0.02              0.05   -0.03     0.04
DAYS >= .01         8               7.9     0.1       10
DAYS >= .10         3               4.1    -1.1        3
DAYS >= .50         0               0.7    -0.7        0
DAYS >= 1.00        0               0.1    -0.1        0
GREATEST
 24 HR. TOTAL    0.16   09/18 TO 09/18

DEGREE_DAYS
HEATING TOTAL      78               132     -54      109
 SINCE 7/1         85               217    -132      130
COOLING TOTAL      75                21      54        3
 SINCE 1/1        392               189     203      291
.................................................................

WIND (MPH)
AVERAGE WIND SPEED              6.6
HIGHEST WIND SPEED/DIRECTION    23/210    DATE  09/30
HIGHEST GUST SPEED/DIRECTION    30/240    DATE  09/19

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.60
NUMBER OF DAYS FAIR            8
NUMBER OF DAYS PC             11
NUMBER OF DAYS CLOUDY         11

AVERAGE RH (PERCENT)     65

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              0     MIXED PRECIP               0
HEAVY RAIN                0     RAIN                       1
LIGHT RAIN                9     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                0     SLEET                      0
FOG                       8     FOG W/VIS <= 1/4 MILE      0
HAZE                      5

-  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.