NWS CLI archive · settlement source
CLIIAD · 워싱턴 D.C. · America/New_York · ← 2026-09-26 · 2026-09-28 → · All dates for KIAD · JSON · METAR-derived record
Final issued 2026-09-28 02:39:00 EDT · Product id iem:CDUS41-KLWX-280639:IAD:2026-09-27:final · IEM archive
Product id iem:CDUS41-KLWX-280639:IAD:2026-09-27:final · iem-afos · IEM archive
SHA-256 4c11cb84e7bc3fcac3ff14fd454717b59d8aa272d6376637db36670fb71105a0
Product text
CDUS41 KLWX 280639
CLIIAD
CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
239 AM EDT MON SEP 28 2026
...................................
...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR SEPTEMBER 27 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 67 11:28 AM 96 1998 75 -8 77
MINIMUM 60 10:49 PM 35 1984 53 7 64
AVERAGE 64 64 0 71
PRECIPITATION (IN)
YESTERDAY 0.03 1.55 1985 0.14 -0.11 T
MONTH TO DATE 3.80 3.51 0.29 1.22
SINCE SEP 1 3.80 3.51 0.29 1.22
SINCE JAN 1 33.20 32.73 0.47 25.86
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 1 3 -2 0
MONTH TO DATE 21 31 -10 7
SINCE SEP 1 21 31 -10 7
SINCE JUL 1 21 32 -11 9
COOLING
YESTERDAY 0 2 -2 6
MONTH TO DATE 191 145 46 150
SINCE SEP 1 191 145 46 150
SINCE JAN 1 1471 1201 270 1298
...................................................................
WIND (MPH)
HIGHEST WIND SPEED 23 HIGHEST WIND DIRECTION NW (320)
HIGHEST GUST SPEED 35 HIGHEST GUST DIRECTION NW (320)
AVERAGE WIND SPEED 12.3
SKY COVER
AVERAGE SKY COVER 1.0
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED YESTERDAY.
LIGHT RAIN
FOG
RELATIVE HUMIDITY (PERCENT)
HIGHEST 93 4:00 PM
LOWEST 61 11:00 AM
AVERAGE 77
..........................................................
THE WASHINGTON DULLES DC CLIMATE NORMALS FOR TODAY
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 75 86 1998
2019
MINIMUM TEMPERATURE (F) 53 34 1989
SUNRISE AND SUNSET
SEPTEMBER 28 2026.....SUNRISE 7:03 AM EDT SUNSET 6:57 PM EDT
SEPTEMBER 29 2026.....SUNRISE 7:04 AM EDT SUNSET 6:55 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-272126:IAD:2026-09-27:interim · iem-afos · IEM archive
SHA-256 5536155893fcddfe93b6f98f3339872e8f88204e0e73460cc79b9b027748857e
Product text
CDUS41 KLWX 272126
CLIIAD
CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
526 PM EDT SUN SEP 27 2026
...................................
...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR SEPTEMBER 27 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 67 11:28 AM 96 1998 75 -8 77
MINIMUM 60 12:23 AM 35 1984 53 7 64
AVERAGE 64 64 0 71
PRECIPITATION (IN)
TODAY 0.01 1.55 1985 0.14 -0.13 T
MONTH TO DATE 3.78 3.51 0.27 1.22
SINCE SEP 1 3.78 3.51 0.27 1.22
SINCE JAN 1 33.18 32.73 0.45 25.86
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 1 3 -2 0
MONTH TO DATE 21 31 -10 7
SINCE SEP 1 21 31 -10 7
SINCE JUL 1 21 32 -11 9
COOLING
TODAY 0 2 -2 6
MONTH TO DATE 191 145 46 150
SINCE SEP 1 191 145 46 150
SINCE JAN 1 1471 1201 270 1298
...................................................................
WIND (MPH)
HIGHEST WIND SPEED 23 HIGHEST WIND DIRECTION NW (320)
HIGHEST GUST SPEED 35 HIGHEST GUST DIRECTION NW (320)
AVERAGE WIND SPEED 13.3
SKY COVER
AVERAGE SKY COVER 0.9
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED TODAY.
LIGHT RAIN
FOG
RELATIVE HUMIDITY (PERCENT)
HIGHEST 93 4:00 PM
LOWEST 61 11:00 AM
AVERAGE 77
..........................................................
THE WASHINGTON DULLES DC CLIMATE NORMALS FOR TOMORROW
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 75 86 1998
2019
MINIMUM TEMPERATURE (F) 53 34 1989
SUNRISE AND SUNSET
SEPTEMBER 27 2026.....SUNRISE 7:02 AM EDT SUNSET 6:59 PM EDT
SEPTEMBER 28 2026.....SUNRISE 7:03 AM EDT SUNSET 6:57 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/2026-09-27 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.