NWS CLI archive · settlement source
CLISEA · 시애틀 · America/Los_Angeles · ← 2026-09-16 · 2026-09-18 → · All dates for KSEA · JSON · METAR-derived record
Final issued 2026-09-18 04:27:00 EDT · Product id iem:CDUS46-KSEW-180827:SEA:2026-09-17:final · IEM archive
Product id iem:CDUS46-KSEW-180827:SEA:2026-09-17:final · iem-afos · IEM archive
SHA-256 b6d3dcbe605c188de36846f038719a16cb5bbd229d9629a1c5c8a6068fe6e3cd
Product text
CDUS46 KSEW 180827
CLISEA
CLIMATE REPORT
NATIONAL WEATHER SERVICE SEATTLE
127 AM PDT FRI SEP 18 2026
...................................
...THE SEATTLE-TACOMA WA AIRPORT CLIMATE SUMMARY FOR SEPTEMBER 17 2026...
CLIMATE NORMAL PERIOD 1991 TO 2020
CLIMATE RECORD PERIOD 1945 TO 2026
WEATHER ITEM OBSERVED TIME RECORD YEAR NORMAL DEPARTURE LAST
VALUE (LST) VALUE VALUE FROM YEAR
NORMAL
...................................................................
TEMPERATURE (F)
YESTERDAY
MAXIMUM 77 341 PM 85 1991 72 5 78
MINIMUM 54 557 AM 41 1947 54 0 59
AVERAGE 66 62 4 69
PRECIPITATION (IN)
YESTERDAY 0.00 1.49 2010 0.06 -0.06 0.00
MONTH TO DATE 1.03 0.80 0.23 0.06
SINCE OCT 1 37.94 38.53 -0.59 28.97
SINCE JAN 1 21.16 22.59 -1.43 15.57
SNOWFALL (IN)
YESTERDAY 0.0 MM MM 0.0
MONTH TO DATE 0.0 0.0
SINCE OCT 1 3.0 2.3
SINCE JUL 1 0.0 0.0
SNOW DEPTH 0
DEGREE DAYS
HEATING
YESTERDAY 0 3 -3 0
MONTH TO DATE 46 39 7 11
SINCE SEP 1 46 39 7 11
SINCE JUL 1 71 94 -23 35
COOLING
YESTERDAY 1 1 0 4
MONTH TO DATE 2 26 -24 34
SINCE SEP 1 2 26 -24 34
SINCE JAN 1 267 259 8 328
...................................................................
WIND (MPH)
RESULTANT WIND SPEED 3 RESULTANT WIND DIRECTION N (350)
HIGHEST WIND SPEED 13 HIGHEST WIND DIRECTION N (360)
HIGHEST GUST SPEED 16 HIGHEST GUST DIRECTION NE (30)
AVERAGE WIND SPEED 5.8
SKY COVER
AVERAGE SKY COVER 0.1
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED YESTERDAY.
NO SIGNIFICANT WEATHER WAS OBSERVED.
RELATIVE HUMIDITY (PERCENT)
HIGHEST 90 500 AM
LOWEST 42 700 PM
AVERAGE 66
..........................................................
THE SEATTLE-TACOMA WA AIRPORT CLIMATE NORMALS FOR TODAY
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 71 85 1991
MINIMUM TEMPERATURE (F) 53 38 1947
SUNRISE AND SUNSET
SEPTEMBER 18 2026.....SUNRISE 651 AM PDT SUNSET 715 PM PDT
SEPTEMBER 19 2026.....SUNRISE 652 AM PDT SUNSET 713 PM PDT
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
$$Product id iem:CDUS46-KSEW-180118:SEA:2026-09-17:interim · iem-afos · IEM archive
SHA-256 f212031845639db4bf2f09dd73eb6faa47babd29d59140c31d22fab98b780723
Product text
CDUS46 KSEW 180118
CLISEA
CLIMATE REPORT
NATIONAL WEATHER SERVICE SEATTLE
618 PM PDT THU SEP 17 2026
...................................
...THE SEATTLE-TACOMA WA AIRPORT CLIMATE SUMMARY FOR SEPTEMBER 17 2026...
VALID TODAY AS OF 0500 PM LOCAL TIME.
CLIMATE NORMAL PERIOD 1991 TO 2020
CLIMATE RECORD PERIOD 1945 TO 2026
WEATHER ITEM OBSERVED TIME RECORD YEAR NORMAL DEPARTURE LAST
VALUE (LST) VALUE VALUE FROM YEAR
NORMAL
...................................................................
TEMPERATURE (F)
TODAY
MAXIMUM 77 341 PM 85 1991 72 5 78
MINIMUM 54 557 AM 41 1947 54 0 59
AVERAGE 66 62 4 69
PRECIPITATION (IN)
TODAY 0.00 1.49 2010 0.06 -0.06 0.00
MONTH TO DATE 1.03 0.80 0.23 0.06
SINCE OCT 1 37.94 38.53 -0.59 28.97
SINCE JAN 1 21.16 22.59 -1.43 15.57
SNOWFALL (IN)
TODAY 0.0 MM MM 0.0
MONTH TO DATE 0.0 0.0
SINCE OCT 1 3.0 2.3
SINCE JUL 1 0.0 0.0
SNOW DEPTH 0
DEGREE DAYS
HEATING
TODAY 0 3 -3 0
MONTH TO DATE 46 39 7 11
SINCE SEP 1 46 39 7 11
SINCE JUL 1 71 94 -23 35
COOLING
TODAY 1 1 0 4
MONTH TO DATE 2 26 -24 34
SINCE SEP 1 2 26 -24 34
SINCE JAN 1 267 259 8 328
...................................................................
WIND (MPH)
RESULTANT WIND SPEED 4 RESULTANT WIND DIRECTION N (350)
HIGHEST WIND SPEED 13 HIGHEST WIND DIRECTION N (360)
HIGHEST GUST SPEED 16 HIGHEST GUST DIRECTION NE (30)
AVERAGE WIND SPEED 6.6
SKY COVER
AVERAGE SKY COVER 0.1
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED TODAY.
NO SIGNIFICANT WEATHER WAS OBSERVED.
RELATIVE HUMIDITY (PERCENT)
HIGHEST 90 500 AM
LOWEST 43 400 PM
AVERAGE 67
..........................................................
THE SEATTLE-TACOMA WA AIRPORT CLIMATE NORMALS FOR TOMORROW
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 71 85 1991
MINIMUM TEMPERATURE (F) 53 38 1947
SUNRISE AND SUNSET
SEPTEMBER 17 2026.....SUNRISE 650 AM PDT SUNSET 717 PM PDT
SEPTEMBER 18 2026.....SUNRISE 651 AM PDT SUNSET 715 PM PDT
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
$$Settlement source: the final NWS Climatological Report (CLI) for station KSEA for the contract date, as archived verbatim at https://weathermarket.io/nws-cli/KSEA/2026-09-17 with links to the NWS product and the IEM archive. A CORRECTED re-issue published before the settlement time supersedes earlier issues.
The settlement value for a date is the latest final CLI issued for that date; a corrected re-issue supersedes earlier issues. Interim same-day products never settle. This is the same rule that fills values.nwsOfficial in /api/station/{icao}/daily.
Every issue is stored verbatim as received - nothing is edited or re-derived. Products are held from 2026-09-01 (backfilled from the IEM AFOS archive) and ingested live from api.weather.gov since 2026-11-10, polled every 30 minutes. A date with no final CLI 14 hours after local midnight is reported as not_issued rather than filled in.