NWS Settlement Weather: Official Daily High/Low by Station

What it does: returns the official NWS daily climate values used to settle weather contracts: the daily high, low and precipitation from the National Weather Service Daily Climate Report (CLI). You get them for the exact climate stations in major US cities (Central Park for New York, Midway for Chicago, and so on), plus a live running max/min from today's station observations. Each record has a settled flag. It is true only once the NWS has issued the final CLI for that day; a same-day afternoon report is labelled preliminary.

Why use it instead of scraping weather sites: the values come straight from the NWS products (no third-party weather site), the day boundaries follow the CLI's local standard time rule (midnight to midnight standard time, even during daylight saving time), and the issuance time and product id of the report behind each value are included so you can audit it.

Use cases

• Check how a daily temperature contract settled. Weather contracts on prediction markets and weather derivatives are commonly settled on the NWS Daily Climate Report for one named station. This Actor returns that report's high, low and precipitation, and tells you whether the value is final.
• Track the day as it happens. The running max/min from live station observations shows where today's high and low stand before the official report is out.
• Audit a value. Each record carries the product id, issuance time and source URLs of the NWS report behind it.
• Give an AI agent the official number. One call returns a small JSON record per station and day.

Tutorial: Why the "official" daily high is not what your weather app says

Supported stations

ICAO	City	CLI code		ICAO	City	CLI code
KNYC	New York (Central Park)	NYC		KATL	Atlanta	ATL
KMDW	Chicago (Midway)	MDW		KDFW	Dallas/Fort Worth	DFW
KORD	Chicago (O'Hare)	ORD		KSEA	Seattle	SEA
KMIA	Miami	MIA		KSFO	San Francisco (SFO)	SFO
KAUS	Austin (Bergstrom)	AUS		KLAS	Las Vegas	LAS
KLAX	Los Angeles (LAX)	LAX		KDCA	Washington DC (Reagan National)	DCA
KDEN	Denver	DEN		KMSY	New Orleans	MSY
KPHL	Philadelphia	PHL		KPHX	Phoenix	PHX
KHOU	Houston (Hobby)	HOU		KMSP	Minneapolis	MSP
KBOS	Boston	BOS		KSAT	San Antonio	SAT
				KOKC	Oklahoma City	OKC

You can pass the ICAO id, the CLI code, or the city name. "Chicago" means Midway (KMDW), and "Houston" means Hobby (KHOU). Use "KORD" for O'Hare.

Input

{
  "locations": ["KNYC", "Chicago", "Austin"],
  "startDate": "yesterday",
  "endDate": "today",
  "includeObservations": false
}

• locations: up to 25 cities or station ids.
• startDate / endDate: YYYY-MM-DD, today or yesterday, in each station's local standard time. endDate defaults to startDate. Dates must be within the last 7 days and not in the future.
• includeObservations: also return every observation of the day (time, °F, raw METAR when present).

Output

One record per station per date (a "station-day"). Real example (KNYC, 2026-10-08):

{
  "station": "KNYC",
  "city": "New York (Central Park)",
  "cli_station_name": "CENTRAL PARK NY",
  "date": "2026-10-08",
  "day_timezone": "UTC-5 (local standard time, as the CLI uses)",
  "settled": true,
  "status": "settled",
  "cli_report_type": "final",
  "cli_valid_as_of": null,
  "cli_high_f": 73,
  "cli_high_time_lst": "251 PM",
  "cli_low_f": 57,
  "cli_low_time_lst": "626 AM",
  "cli_precip_in": 0.0,
  "cli_precip_trace": false,
  "cli_record_high": false,
  "cli_record_low": false,
  "cli_product_id": "11381994-8a82-44f7-a5f5-1e40d6d5d94b",
  "cli_issued_at": "2026-10-09T06:32:00Z",
  "obs_high_f": 73.0,
  "obs_low_f": 57.0,
  "obs_count": 24,
  "obs_first_utc": "2026-10-08T05:51:00Z",
  "obs_last_utc": "2026-10-09T04:51:00Z",
  "obs_source": "api.weather.gov",
  "source_urls": [
    "https://api.weather.gov/products/11381994-8a82-44f7-a5f5-1e40d6d5d94b",
    "https://api.weather.gov/stations/KNYC/observations?start=2026-10-08T05%3A00%3A00Z&end=2026-10-09T05%3A00%3A00Z&limit=500"
  ],
  "fetched_at": "2026-10-09T14:21:40Z"
}

Field	Meaning
settled	true when the final CLI for that date has been issued (normally early the next morning, local time).
status	Why the row is or isn't settled, in plain words: settled; preliminary as of 7 AM (a same-day CLI that covers only part of the day); pending: day not over, final report expected after midnight local standard time (today, no CLI yet, so the cli_* columns are empty); pending: final report not issued yet (yesterday, final still to come); or no report: NWS has not issued a CLI for this date.
cli_report_type	final, preliminary (a same-day CLI "valid as of" a local time), or null when no CLI for that date has been issued yet.
cli_high_f, cli_low_f, cli_precip_in	Values from that CLI. null if the report shows them as missing (MM). A trace of precipitation is 0.0 with cli_precip_trace: true.
cli_high_time_lst, cli_low_time_lst	Time of the extreme as printed in the CLI (local standard time).
cli_record_high, cli_record_low	true if the CLI marks the value as a record (R).
obs_high_f, obs_low_f	Running max/min of the reported observation temperatures for that local-standard-time day, so far.
obs_source	api.weather.gov, or aviationweather.gov if the NWS observations endpoint was down and the METAR fallback was used.

FAQ

Which station is used for New York's daily high temperature? Contracts that reference the NWS Daily Climate Report for New York use Central Park (KNYC). Chicago contracts usually name Midway (KMDW), not O'Hare. Always check the station named in your own contract's rules; this Actor returns whichever supported station you ask for.

Why is the official high different from my weather app? Two reasons. The climate day runs midnight to midnight local standard time, so during daylight saving time it runs from 1 AM to 1 AM on the clock. And the official value comes from the station's continuous record, while apps usually show periodic observations or a nearby station.

When is the final value available? The morning after. In our October 2026 tests, NWS offices issued the final report between about 1 AM and 5 AM local time. Until then settled is false.

What does settled: false mean? The final Daily Climate Report for that date has not been issued yet. status says why: the day is not over, the final report is still to come, a same-day preliminary report is all there is, or the NWS has issued no report.

Can I use the obs_* values for settlement? No. They are a running max/min from reported observations and can differ from the official value by a degree or so. Use the cli_* fields for settlement and obs_* for intraday tracking.

Can I get dates older than a week? No. The NWS API keeps these reports and observations for about 7 days.

Does it return market prices or odds? No. It returns weather data only.

Pricing

Pay per event:

• $0.005 per run (start).
• $0.002 per station-day record.

Example: 3 cities for yesterday and today = 6 records = $0.005 + 6 × $0.002 = $0.017. You are only charged for records returned.

Limits

• 7-day window. The NWS API keeps CLI reports and observations for about 7 days. Older dates are refused, and no station-day records are charged for them (the per-run start fee still applies).
• Final values arrive the next morning. Until the final CLI is issued, settled is false and status says why. For today the cli_* columns are often empty (no CLI yet) or hold a partial morning/afternoon report; for settled values, ask for yesterday. NWS offices issue it at different times; in our October 2026 tests, between about 1 AM and 5 AM local time. Offices occasionally re-issue or correct a CLI later; this Actor always returns the latest final report it finds.
• Observation max/min is not the official value. The CLI high/low comes from the station's continuous record. The running max/min comes from the reported observations (usually every 5 minutes, hourly for some stations, converted from °C to °F to one decimal). It can differ from the official value by a degree or so. Use cli_* fields for settlement and obs_* for intraday tracking.
• Raw METAR text is present only on the hourly/special observations, not on 5-minute ones.
• Only the stations listed above. Other stations are refused.
• Upstream outages. If api.weather.gov is down for the CLI, that location is skipped with a warning and no station-day records are charged for it. If only the observations endpoint is down, observations come from aviationweather.gov instead.

Data source

All data comes from US federal government sources and is in the public domain:

• National Weather Service API, api.weather.gov: CLI daily climate report products and station observations.
• NOAA Aviation Weather Center data API, aviationweather.gov: METAR observations, as a fallback.

This Actor is not affiliated with or endorsed by NOAA or the NWS. It returns weather data only, no market data.