NWS CLI archive · settlement source
CLIIAD · 워싱턴 D.C. · America/New_York · ← 2026-09-27 · 2026-09-29 → · All dates for KIAD · JSON · METAR-derived record
Final issued 2026-09-29 02:26:00 EDT · Product id iem:CDUS41-KLWX-290626:IAD:2026-09-28:final · IEM archive
Product id iem:CDUS41-KLWX-290626:IAD:2026-09-28:final · iem-afos · IEM archive
SHA-256 8fc8979a88934d9930e848cae468ab84da6944de7258facbb04eec720f37c1b8
Product text
CDUS41 KLWX 290626
CLIIAD
CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
226 AM EDT TUE SEP 29 2026
...................................
...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR SEPTEMBER 28 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 71 5:14 PM 86 1998 75 -4 85
2019
MINIMUM 61 6:45 AM 34 1989 53 8 62
AVERAGE 66 64 2 74
PRECIPITATION (IN)
YESTERDAY 0.00 1.61 2004 0.14 -0.14 0.00
MONTH TO DATE 3.80 3.65 0.15 1.22
SINCE SEP 1 3.80 3.65 0.15 1.22
SINCE JAN 1 33.20 32.87 0.33 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 35 -14 7
SINCE SEP 1 21 35 -14 7
SINCE JUL 1 21 36 -15 9
COOLING
YESTERDAY 1 2 -1 9
MONTH TO DATE 192 147 45 159
SINCE SEP 1 192 147 45 159
SINCE JAN 1 1472 1203 269 1307
...................................................................
WIND (MPH)
HIGHEST WIND SPEED 14 HIGHEST WIND DIRECTION W (290)
HIGHEST GUST SPEED 21 HIGHEST GUST DIRECTION W (290)
AVERAGE WIND SPEED 7.9
SKY COVER
AVERAGE SKY COVER 0.9
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED YESTERDAY.
NO SIGNIFICANT WEATHER WAS OBSERVED.
RELATIVE HUMIDITY (PERCENT)
HIGHEST 90 12:00 AM
LOWEST 63 2:00 PM
AVERAGE 77
..........................................................
THE WASHINGTON DULLES DC CLIMATE NORMALS FOR TODAY
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 74 89 2019
MINIMUM TEMPERATURE (F) 52 34 1978
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.
$$Product id iem:CDUS41-KLWX-282126:IAD:2026-09-28:interim · iem-afos · IEM archive
SHA-256 3c17c2b934caf162a2ec3dc5a9c7e377ab5767ae972f2edbbc4ac7f320023a1f
Product text
CDUS41 KLWX 282126
CLIIAD
CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
526 PM EDT MON SEP 28 2026
...................................
...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR SEPTEMBER 28 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 71 1:53 PM 86 1998 75 -4 85
2019
MINIMUM 61 6:45 AM 34 1989 53 8 62
AVERAGE 66 64 2 74
PRECIPITATION (IN)
TODAY 0.00 1.61 2004 0.14 -0.14 0.00
MONTH TO DATE 3.80 3.65 0.15 1.22
SINCE SEP 1 3.80 3.65 0.15 1.22
SINCE JAN 1 33.20 32.87 0.33 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 35 -14 7
SINCE SEP 1 21 35 -14 7
SINCE JUL 1 21 36 -15 9
COOLING
TODAY 1 2 -1 9
MONTH TO DATE 192 147 45 159
SINCE SEP 1 192 147 45 159
SINCE JAN 1 1472 1203 269 1307
...................................................................
WIND (MPH)
HIGHEST WIND SPEED 14 HIGHEST WIND DIRECTION W (290)
HIGHEST GUST SPEED 21 HIGHEST GUST DIRECTION W (290)
AVERAGE WIND SPEED 8.5
SKY COVER
AVERAGE SKY COVER 0.9
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED TODAY.
NO SIGNIFICANT WEATHER WAS OBSERVED.
RELATIVE HUMIDITY (PERCENT)
HIGHEST 90 12:00 AM
LOWEST 63 2:00 PM
AVERAGE 77
..........................................................
THE WASHINGTON DULLES DC CLIMATE NORMALS FOR TOMORROW
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 74 89 2019
MINIMUM TEMPERATURE (F) 52 34 1978
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.
$$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/2026-09-28 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.