NWS CLI archive · settlement source
CLIIAD · 워싱턴 D.C. · America/New_York · ← 2026-08-30 · 2026-09-01 → · All dates for KIAD · JSON · METAR-derived record
Final issued 2026-09-01 02:28:00 EDT · Product id iem:CDUS41-KLWX-010628:IAD:2026-08-31:final · IEM archive
Product id iem:CDUS41-KLWX-010628:IAD:2026-08-31:final · iem-afos · IEM archive
SHA-256 1de69fe10e338a225c11d5193bc5253c2c094d142a0d679e23225e4a19f0a8ce
Product text
CDUS41 KLWX 010628
CLIIAD
CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
228 AM EDT TUE SEP 01 2026
...................................
...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR AUGUST 31 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 1:04 PM 98 1991 84 2 79
MINIMUM 69 4:41 AM 43 1976 63 6 48
AVERAGE 78 74 4 64
PRECIPITATION (IN)
YESTERDAY T 3.21 1975 0.11 -0.11 0.00
MONTH TO DATE 4.85 3.53 1.32 0.85
SINCE JUN 1 14.48 11.98 2.50 10.72
SINCE JAN 1 29.40 29.22 0.18 24.64
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 JUN 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 1
MONTH TO DATE 0 0 0 2
SINCE JUN 1 1 13 -12 17
SINCE JUL 1 0 0 0 2
COOLING
YESTERDAY 13 9 4 0
MONTH TO DATE 394 334 60 232
SINCE JUN 1 1107 950 157 1030
SINCE JAN 1 1280 1056 224 1148
...................................................................
WIND (MPH)
HIGHEST WIND SPEED 10 HIGHEST WIND DIRECTION N (10)
HIGHEST GUST SPEED 13 HIGHEST GUST DIRECTION N (360)
AVERAGE WIND SPEED 2.7
SKY COVER
AVERAGE SKY COVER 0.8
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED YESTERDAY.
LIGHT RAIN
RELATIVE HUMIDITY (PERCENT)
HIGHEST 100 1:00 AM
LOWEST 61 5:00 PM
AVERAGE 81
..........................................................
THE WASHINGTON DULLES DC CLIMATE NORMALS FOR TODAY
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 84 98 1962
1980
MINIMUM TEMPERATURE (F) 63 49 1970
1976
SUNRISE AND SUNSET
SEPTEMBER 1 2026.....SUNRISE 6:39 AM EDT SUNSET 7:40 PM EDT
SEPTEMBER 2 2026.....SUNRISE 6:40 AM EDT SUNSET 7:39 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/2026-08-31 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.