NWS CLI archive · settlement source
CLIIAD · 워싱턴 D.C. · America/New_York · ← 2026-09-28 · 2026-09-30 → · All dates for KIAD · JSON · METAR-derived record
Final issued 2026-09-30 02:27:00 EDT · Product id iem:CDUS41-KLWX-300627:IAD:2026-09-29:final · IEM archive
Product id iem:CDUS41-KLWX-300627:IAD:2026-09-29:final · iem-afos · IEM archive
SHA-256 7710fe2e9077d04c5e15811142b973d8b3deca52a1e1ec5f2b36243192dcb3ce
Product text
CDUS41 KLWX 300627
CLIIAD
CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
227 AM EDT WED SEP 30 2026
...................................
...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR SEPTEMBER 29 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 74 4:22 PM 89 2019 74 0 79
MINIMUM 60 11:59 PM 34 1978 52 8 60
AVERAGE 67 63 4 70
PRECIPITATION (IN)
YESTERDAY 0.00 2.23 1963 0.14 -0.14 0.00
MONTH TO DATE 3.80 3.79 0.01 1.22
SINCE SEP 1 3.80 3.79 0.01 1.22
SINCE JAN 1 33.20 33.01 0.19 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 0 4 -4 0
MONTH TO DATE 21 39 -18 7
SINCE SEP 1 21 39 -18 7
SINCE JUL 1 21 40 -19 9
COOLING
YESTERDAY 2 2 0 5
MONTH TO DATE 194 149 45 164
SINCE SEP 1 194 149 45 164
SINCE JAN 1 1474 1205 269 1312
...................................................................
WIND (MPH)
HIGHEST WIND SPEED 13 HIGHEST WIND DIRECTION NW (320)
HIGHEST GUST SPEED 17 HIGHEST GUST DIRECTION NW (320)
AVERAGE WIND SPEED 3.3
SKY COVER
AVERAGE SKY COVER 0.8
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED YESTERDAY.
NO SIGNIFICANT WEATHER WAS OBSERVED.
RELATIVE HUMIDITY (PERCENT)
HIGHEST 90 11:00 PM
LOWEST 64 4:00 PM
AVERAGE 77
..........................................................
THE WASHINGTON DULLES DC CLIMATE NORMALS FOR TODAY
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 74 92 1986
MINIMUM TEMPERATURE (F) 52 35 1993
SUNRISE AND SUNSET
SEPTEMBER 30 2026.....SUNRISE 7:05 AM EDT SUNSET 6:54 PM EDT
OCTOBER 1 2026.......SUNRISE 7:06 AM EDT SUNSET 6:52 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-292126:IAD:2026-09-29:interim · iem-afos · IEM archive
SHA-256 39dae1100d8e1b126d1abddc8e8a895b95eb5aac2d9be4b0446833c9eec28649
Product text
CDUS41 KLWX 292126
CLIIAD
CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
526 PM EDT TUE SEP 29 2026
...................................
...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR SEPTEMBER 29 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 73 3:04 PM 89 2019 74 -1 79
MINIMUM 61 5:43 AM 34 1978 52 9 60
AVERAGE 67 63 4 70
PRECIPITATION (IN)
TODAY 0.00 2.23 1963 0.14 -0.14 0.00
MONTH TO DATE 3.80 3.79 0.01 1.22
SINCE SEP 1 3.80 3.79 0.01 1.22
SINCE JAN 1 33.20 33.01 0.19 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 0 4 -4 0
MONTH TO DATE 21 39 -18 7
SINCE SEP 1 21 39 -18 7
SINCE JUL 1 21 40 -19 9
COOLING
TODAY 2 2 0 5
MONTH TO DATE 194 149 45 164
SINCE SEP 1 194 149 45 164
SINCE JAN 1 1474 1205 269 1312
...................................................................
WIND (MPH)
HIGHEST WIND SPEED 13 HIGHEST WIND DIRECTION NW (320)
HIGHEST GUST SPEED 17 HIGHEST GUST DIRECTION NW (320)
AVERAGE WIND SPEED 4.1
SKY COVER
AVERAGE SKY COVER 0.9
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED TODAY.
NO SIGNIFICANT WEATHER WAS OBSERVED.
RELATIVE HUMIDITY (PERCENT)
HIGHEST 87 7:00 AM
LOWEST 64 4:00 PM
AVERAGE 76
..........................................................
THE WASHINGTON DULLES DC CLIMATE NORMALS FOR TOMORROW
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 74 92 1986
MINIMUM TEMPERATURE (F) 52 35 1993
SUNRISE AND SUNSET
SEPTEMBER 29 2026.....SUNRISE 7:04 AM EDT SUNSET 6:55 PM EDT
SEPTEMBER 30 2026.....SUNRISE 7:05 AM EDT SUNSET 6:54 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/2026-09-29 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.