NWS CLI archive · settlement source
CLIIAD · 워싱턴 D.C. · America/New_York · ← 2026-09-07 · 2026-09-09 → · All dates for KIAD · JSON · METAR-derived record
Final issued 2026-09-09 02:31:00 EDT · Product id iem:CDUS41-KLWX-090631:IAD:2026-09-08:final · IEM archive
Product id iem:CDUS41-KLWX-090631:IAD:2026-09-08:final · iem-afos · IEM archive
SHA-256 afc0d492ee1df5961ee5b971de67d8052dd574884521af06eb1642217c20008d
Product text
CDUS41 KLWX 090631
CLIIAD
CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
231 AM EDT WED SEP 09 2026
...................................
...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR SEPTEMBER 8 2026...
CLIMATE NORMAL PERIOD: 1991 TO 2020
CLIMATE RECORD PERIOD: 1960 TO 2026
WEATHER ITEM OBSERVED TIME RECORD YEAR NORMAL DEPARTURE LAST
VALUE (LST) VALUE VALUE FROM YEAR
NORMAL
...................................................................
TEMPERATURE (F)
YESTERDAY
MAXIMUM 86 3:49 PM 96 2016 82 4 76
MINIMUM 57 5:59 AM 43 1984 61 -4 47
AVERAGE 72 72 0 62
PRECIPITATION (IN)
YESTERDAY 0.00 3.56 1987 0.12 -0.12 0.00
MONTH TO DATE 0.83 0.97 -0.14 0.03
SINCE SEP 1 0.83 0.97 -0.14 0.03
SINCE JAN 1 30.23 30.19 0.04 24.67
SNOWFALL (IN)
YESTERDAY 0.0 MM MM 0.0 0.0 0.0
MONTH TO DATE 0.0 0.0 0.0 0.0
SINCE SEP 1 0.0 0.0 0.0 0.0
SINCE JUL 1 0.0 0.0 0.0 0.0
SNOW DEPTH 0
DEGREE DAYS
HEATING
YESTERDAY 0 0 0 3
MONTH TO DATE 0 0 0 3
SINCE SEP 1 0 0 0 3
SINCE JUL 1 0 1 -1 5
COOLING
YESTERDAY 7 7 0 0
MONTH TO DATE 98 61 37 38
SINCE SEP 1 98 61 37 38
SINCE JAN 1 1378 1117 261 1186
...................................................................
WIND (MPH)
HIGHEST WIND SPEED 9 HIGHEST WIND DIRECTION S (190)
HIGHEST GUST SPEED 18 HIGHEST GUST DIRECTION SW (230)
AVERAGE WIND SPEED 3.3
SKY COVER
AVERAGE SKY COVER 0.4
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED YESTERDAY.
NO SIGNIFICANT WEATHER WAS OBSERVED.
RELATIVE HUMIDITY (PERCENT)
HIGHEST 97 3:00 AM
LOWEST 45 4:00 PM
AVERAGE 71
..........................................................
THE WASHINGTON DULLES DC CLIMATE NORMALS FOR TODAY
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 82 98 2016
MINIMUM TEMPERATURE (F) 61 40 1986
SUNRISE AND SUNSET
SEPTEMBER 9 2026.....SUNRISE 6:46 AM EDT SUNSET 7:28 PM EDT
SEPTEMBER 10 2026.....SUNRISE 6:47 AM EDT SUNSET 7:26 PM EDT
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
$$Product id iem:CDUS41-KLWX-082123:IAD:2026-09-08:interim · iem-afos · IEM archive
SHA-256 76bf576343562259a4a6f0af1cedee2727930d233f9a75cb9ee833ba7a5385be
Product text
CDUS41 KLWX 082123
CLIIAD
CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
523 PM EDT TUE SEP 08 2026
...................................
...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR SEPTEMBER 8 2026...
VALID TODAY AS OF 0500 PM LOCAL TIME.
CLIMATE NORMAL PERIOD: 1991 TO 2020
CLIMATE RECORD PERIOD: 1960 TO 2026
WEATHER ITEM OBSERVED TIME RECORD YEAR NORMAL DEPARTURE LAST
VALUE (LST) VALUE VALUE FROM YEAR
NORMAL
...................................................................
TEMPERATURE (F)
TODAY
MAXIMUM 86 3:49 PM 96 2016 82 4 76
MINIMUM 57 5:59 AM 43 1984 61 -4 47
AVERAGE 72 72 0 62
PRECIPITATION (IN)
TODAY 0.00 3.56 1987 0.12 -0.12 0.00
MONTH TO DATE 0.83 0.97 -0.14 0.03
SINCE SEP 1 0.83 0.97 -0.14 0.03
SINCE JAN 1 30.23 30.19 0.04 24.67
SNOWFALL (IN)
TODAY 0.0 MM MM 0.0 0.0 0.0
MONTH TO DATE 0.0 0.0 0.0 0.0
SINCE SEP 1 0.0 0.0 0.0 0.0
SINCE JUL 1 0.0 0.0 0.0 0.0
SNOW DEPTH 0
DEGREE DAYS
HEATING
TODAY 0 0 0 3
MONTH TO DATE 0 0 0 3
SINCE SEP 1 0 0 0 3
SINCE JUL 1 0 1 -1 5
COOLING
TODAY 7 7 0 0
MONTH TO DATE 98 61 37 38
SINCE SEP 1 98 61 37 38
SINCE JAN 1 1378 1117 261 1186
...................................................................
WIND (MPH)
HIGHEST WIND SPEED 9 HIGHEST WIND DIRECTION S (190)
HIGHEST GUST SPEED 18 HIGHEST GUST DIRECTION SW (230)
AVERAGE WIND SPEED 2.4
SKY COVER
AVERAGE SKY COVER 0.3
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED TODAY.
NO SIGNIFICANT WEATHER WAS OBSERVED.
RELATIVE HUMIDITY (PERCENT)
HIGHEST 97 3:00 AM
LOWEST 45 4:00 PM
AVERAGE 71
..........................................................
THE WASHINGTON DULLES DC CLIMATE NORMALS FOR TOMORROW
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 82 98 2016
MINIMUM TEMPERATURE (F) 61 40 1986
SUNRISE AND SUNSET
SEPTEMBER 8 2026.....SUNRISE 6:45 AM EDT SUNSET 7:29 PM EDT
SEPTEMBER 9 2026.....SUNRISE 6:46 AM EDT SUNSET 7:28 PM EDT
- 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 KIAD for the contract date, as archived verbatim at https://weathermarket.io/nws-cli/KIAD/2026-09-08 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.