NWS CLI archive · settlement source
CLIIAD · 워싱턴 D.C. · America/New_York · ← 2026-09-15 · 2026-09-17 → · All dates for KIAD · JSON · METAR-derived record
Final issued 2026-09-17 02:25:00 EDT · Product id iem:CDUS41-KLWX-170625:IAD:2026-09-16:final · IEM archive
Product id iem:CDUS41-KLWX-170625:IAD:2026-09-16:final · iem-afos · IEM archive
SHA-256 68efd2743629b0608800a376852551f8a438c02297e65941e00ebdf752d9f852
Product text
CDUS41 KLWX 170625
CLIIAD
CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
225 AM EDT THU SEP 17 2026
...................................
...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR SEPTEMBER 16 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 85 4:09 PM 97 1991 79 6 75
MINIMUM 58 3:12 AM 37 1984 58 0 59
AVERAGE 72 69 3 67
PRECIPITATION (IN)
YESTERDAY 0.00 2.05 1999 0.15 -0.15 0.69
MONTH TO DATE 1.42 2.04 -0.62 0.87
SINCE SEP 1 1.42 2.04 -0.62 0.87
SINCE JAN 1 30.82 31.26 -0.44 25.51
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 1 -1 0
MONTH TO DATE 0 7 -7 6
SINCE SEP 1 0 7 -7 6
SINCE JUL 1 0 8 -8 8
COOLING
YESTERDAY 7 5 2 2
MONTH TO DATE 169 107 62 71
SINCE SEP 1 169 107 62 71
SINCE JAN 1 1449 1163 286 1219
...................................................................
WIND (MPH)
HIGHEST WIND SPEED 12 HIGHEST WIND DIRECTION SW (220)
HIGHEST GUST SPEED 18 HIGHEST GUST DIRECTION SW (220)
AVERAGE WIND SPEED 5.2
SKY COVER
AVERAGE SKY COVER 0.1
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED YESTERDAY.
NO SIGNIFICANT WEATHER WAS OBSERVED.
RELATIVE HUMIDITY (PERCENT)
HIGHEST 93 3:00 AM
LOWEST 53 2:00 PM
AVERAGE 73
..........................................................
THE WASHINGTON DULLES DC CLIMATE NORMALS FOR TODAY
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 79 97 1991
MINIMUM TEMPERATURE (F) 58 35 1986
SUNRISE AND SUNSET
SEPTEMBER 17 2026.....SUNRISE 6:53 AM EDT SUNSET 7:15 PM EDT
SEPTEMBER 18 2026.....SUNRISE 6:54 AM EDT SUNSET 7:13 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-162128:IAD:2026-09-16:interim · iem-afos · IEM archive
SHA-256 c8e3d3a94ce79bb7ce9605a05ee5670c446a08a8ae00d5d99b4768b47ad47c2c
Product text
CDUS41 KLWX 162128
CLIIAD
CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
528 PM EDT WED SEP 16 2026
...................................
...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR SEPTEMBER 16 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 85 3:39 PM 97 1991 79 6 75
MINIMUM 58 3:12 AM 37 1984 58 0 59
AVERAGE 72 69 3 67
PRECIPITATION (IN)
TODAY 0.00 2.05 1999 0.15 -0.15 0.69
MONTH TO DATE 1.42 2.04 -0.62 0.87
SINCE SEP 1 1.42 2.04 -0.62 0.87
SINCE JAN 1 30.82 31.26 -0.44 25.51
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 1 -1 0
MONTH TO DATE 0 7 -7 6
SINCE SEP 1 0 7 -7 6
SINCE JUL 1 0 8 -8 8
COOLING
TODAY 7 5 2 2
MONTH TO DATE 169 107 62 71
SINCE SEP 1 169 107 62 71
SINCE JAN 1 1449 1163 286 1219
...................................................................
WIND (MPH)
HIGHEST WIND SPEED 12 HIGHEST WIND DIRECTION SW (220)
HIGHEST GUST SPEED 18 HIGHEST GUST DIRECTION SW (220)
AVERAGE WIND SPEED 5.1
SKY COVER
AVERAGE SKY COVER 0.1
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED TODAY.
NO SIGNIFICANT WEATHER WAS OBSERVED.
RELATIVE HUMIDITY (PERCENT)
HIGHEST 93 3:00 AM
LOWEST 53 2:00 PM
AVERAGE 73
..........................................................
THE WASHINGTON DULLES DC CLIMATE NORMALS FOR TOMORROW
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 79 97 1991
MINIMUM TEMPERATURE (F) 58 35 1986
SUNRISE AND SUNSET
SEPTEMBER 16 2026.....SUNRISE 6:52 AM EDT SUNSET 7:16 PM EDT
SEPTEMBER 17 2026.....SUNRISE 6:53 AM EDT SUNSET 7:15 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/2026-09-16 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.