NWS CLI archive · settlement source
CLIIAD · 워싱턴 D.C. · America/New_York · ← 2026-09-17 · 2026-09-19 → · All dates for KIAD · JSON · METAR-derived record
Final issued 2026-09-19 02:28:00 EDT · Product id iem:CDUS41-KLWX-190628:IAD:2026-09-18:final · IEM archive
Product id iem:CDUS41-KLWX-190628:IAD:2026-09-18:final · iem-afos · IEM archive
SHA-256 2a659eccede9758938656e757554139f6c9e25c583d634b9a0e9addd7e5f688a
Product text
CDUS41 KLWX 190628
CLIIAD
CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
228 AM EDT SAT SEP 19 2026
...................................
...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR SEPTEMBER 18 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 11:43 AM 91 1978 79 7 86
MINIMUM MM MM 37 1990 57 MM 62
AVERAGE MM 68 MM 74
PRECIPITATION (IN)
YESTERDAY T 1.76 2003 0.15 -0.15 0.00
MONTH TO DATE 1.56 2.33 -0.77 1.05
SINCE SEP 1 1.56 2.33 -0.77 1.05
SINCE JAN 1 30.96 31.55 -0.59 25.69
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 MM 2 MM 0
MONTH TO DATE 0 10 -10 7
SINCE SEP 1 0 10 -10 7
SINCE JUL 1 0 11 -11 9
COOLING
YESTERDAY MM 4 MM 9
MONTH TO DATE 169 116 53 80
SINCE SEP 1 169 116 53 80
SINCE JAN 1 1449 1172 277 1228
...................................................................
WIND (MPH)
HIGHEST WIND SPEED 15 HIGHEST WIND DIRECTION N (340)
HIGHEST GUST SPEED 21 HIGHEST GUST DIRECTION N (350)
AVERAGE WIND SPEED 6.5
SKY COVER
AVERAGE SKY COVER 0.7
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED YESTERDAY.
NO SIGNIFICANT WEATHER WAS OBSERVED.
RELATIVE HUMIDITY (PERCENT)
HIGHEST 96 12:00 AM
LOWEST 57 12:00 PM
AVERAGE 77
..........................................................
THE WASHINGTON DULLES DC CLIMATE NORMALS FOR TODAY
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 78 93 1977
1978
MINIMUM TEMPERATURE (F) 57 36 1984
SUNRISE AND SUNSET
SEPTEMBER 19 2026.....SUNRISE 6:55 AM EDT SUNSET 7:12 PM EDT
SEPTEMBER 20 2026.....SUNRISE 6:56 AM EDT SUNSET 7:10 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-182252:IAD:2026-09-18:interim · iem-afos · IEM archive
SHA-256 af150993f4d44fec93891ce97dece68cbbaedcec8a97ff44f1d40ff18cd181d5
Product text
CDUS41 KLWX 182252
CLIIAD
CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
652 PM EDT FRI SEP 18 2026
...................................
...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR SEPTEMBER 18 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 86 11:43 AM 91 1978 79 7 86
MINIMUM MM MM 37 1990 57 MM 62
AVERAGE MM 68 MM 74
PRECIPITATION (IN)
TODAY T 1.76 2003 0.15 -0.15 0.00
MONTH TO DATE 1.56 2.33 -0.77 1.05
SINCE SEP 1 1.56 2.33 -0.77 1.05
SINCE JAN 1 30.96 31.55 -0.59 25.69
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 MM 2 MM 0
MONTH TO DATE 0 10 -10 7
SINCE SEP 1 0 10 -10 7
SINCE JUL 1 0 11 -11 9
COOLING
TODAY MM 4 MM 9
MONTH TO DATE 169 116 53 80
SINCE SEP 1 169 116 53 80
SINCE JAN 1 1449 1172 277 1228
...................................................................
WIND (MPH)
HIGHEST WIND SPEED 15 HIGHEST WIND DIRECTION N (340)
HIGHEST GUST SPEED 21 HIGHEST GUST DIRECTION N (350)
AVERAGE WIND SPEED 6.4
SKY COVER
AVERAGE SKY COVER 0.7
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED TODAY.
NO SIGNIFICANT WEATHER WAS OBSERVED.
RELATIVE HUMIDITY (PERCENT)
HIGHEST 96 12:00 AM
LOWEST 57 12:00 PM
AVERAGE 77
..........................................................
THE WASHINGTON DULLES DC CLIMATE NORMALS FOR TOMORROW
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 78 93 1977
1978
MINIMUM TEMPERATURE (F) 57 36 1984
SUNRISE AND SUNSET
SEPTEMBER 18 2026.....SUNRISE 6:54 AM EDT SUNSET 7:13 PM EDT
SEPTEMBER 19 2026.....SUNRISE 6:55 AM EDT SUNSET 7:12 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-182140:IAD:2026-09-18:interim · iem-afos · IEM archive
SHA-256 87d95c932a8382940a67504deb24c25218bd2e491fd9291739c10cf8b0d354ab
Product text
CDUS41 KLWX 182140
CLIIAD
CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
540 PM EDT FRI SEP 18 2026
...................................
...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR SEPTEMBER 18 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 86 11:43 AM 91 1978 79 7 86
MINIMUM 23R 6:52 AM 37 1990 57 -34 62
AVERAGE 55 68 -13 74
PRECIPITATION (IN)
TODAY T 1.76 2003 0.15 -0.15 0.00
MONTH TO DATE 1.56 2.33 -0.77 1.05
SINCE SEP 1 1.56 2.33 -0.77 1.05
SINCE JAN 1 30.96 31.55 -0.59 25.69
SNOWFALL (IN)
TODAY 0.0 MM 0.0 0.0 MM 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 MM
DEGREE DAYS
HEATING
TODAY 10 2 8 0
MONTH TO DATE 10 10 0 7
SINCE SEP 1 10 10 0 7
SINCE JUL 1 10 11 -1 9
COOLING
TODAY 0 4 -4 9
MONTH TO DATE 169 116 53 80
SINCE SEP 1 169 116 53 80
SINCE JAN 1 1449 1172 277 1228
...................................................................
WIND (MPH)
HIGHEST WIND SPEED 15 HIGHEST WIND DIRECTION N (340)
HIGHEST GUST SPEED 21 HIGHEST GUST DIRECTION N (350)
AVERAGE WIND SPEED 6.3
SKY COVER
AVERAGE SKY COVER 0.7
WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED TODAY.
NO SIGNIFICANT WEATHER WAS OBSERVED.
RELATIVE HUMIDITY (PERCENT)
HIGHEST 96 12:00 AM
LOWEST 57 12:00 PM
AVERAGE 77
..........................................................
THE WASHINGTON DULLES DC CLIMATE NORMALS FOR TOMORROW
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 78 93 1977
1978
MINIMUM TEMPERATURE (F) 57 36 1984
SUNRISE AND SUNSET
SEPTEMBER 18 2026.....SUNRISE 6:54 AM EDT SUNSET 7:13 PM EDT
SEPTEMBER 19 2026.....SUNRISE 6:55 AM EDT SUNSET 7:12 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/2026-09-18 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.