NWS Official Daily High & Low Temperature (CLI)

Get the official National Weather Service daily high and low temperature for any US station, straight from the NWS Daily Climate Report (CLI). Each row also gives the max/min from the station's routine hourly observations and the difference between the hourly figure and the official one.

The two numbers often disagree, and the official one is what counts:

• Climate days run midnight to midnight in local standard time. During daylight saving time that is 1:00 AM to 1:00 AM on the clock, so "yesterday's high" from a weather app or a calendar-day query can cover the wrong 24 hours.
• Hourly observations (METAR) miss peaks between readings. The CLI uses higher-frequency data. On Oct 21, 2026, Central Park (KNYC) peaked at 61°F in the hourly obs, but the official CLI high was 62°F. Chicago Midway (KMDW) went the other way: hourly 72°F, official 71°F.

Who uses it

• Insurance and claims analysts. Verify the official high/low for a date of loss (freeze, heat, frost claims) and keep the NWS product id as a citation.
• Weather-derivative and temperature-contract traders. Check the official settlement value, see in-progress provisional highs/lows, and map them to your own bucket grid (e.g. gte62lt63). This actor reads public NWS data only. It does not fetch or resell market prices and gives no trading advice.
• Energy analysts. Daily highs/lows for heating/cooling degree days and load reconciliation, on the official climate-day basis.
• Researchers and data teams. Build datasets that compare hourly-observation extremes with official values across stations.
• AI agents and automations. A clean JSON answer to "what was the official high at KXXX yesterday?" through the Apify API or Apify MCP server, with pay-per-result pricing and no subscription.

What you get per station-day

Field	Meaning
station, stationName, timeZone	NWS station (ICAO id such as KNYC)
climateDate, window.startUTC, window.endUTC	The exact official climate-day window
status	in_progress or day_complete
officialCLI	Official maxF / minF with times, final (true = the settled daily value), issued, productId and bucket labels
provisionalHigh, provisionalLow	Max/min from hourly station observations, with the raw value, time and bucket
officialVsHourly	highDiff / lowDiff (official minus hourly, °F) and highMatches / lowMatches
bucketRule	Your bucket width/offset or custom edges

Sample output (trimmed)

{
  "station": "KNYC",
  "stationName": "New York City, Central Park",
  "climateDate": "2026-10-21",
  "status": "day_complete",
  "provisionalHigh": { "value": 61, "raw": 61, "at": "2026-10-21T20:51:00+00:00", "bucket": { "label": "gte61lt62" } },
  "provisionalLow": { "value": 50, "raw": 50, "at": "2026-10-21T11:51:00+00:00", "bucket": { "label": "gte50lt51" } },
  "officialCLI": { "final": true, "issued": "2026-10-22T06:17:00+00:00", "maxF": 62, "maxTimeLST": "315 PM", "minF": 50, "minTimeLST": "743 AM", "productId": "ac336748-d9a0-43ab-ae63-639f19c3ebb6" },
  "officialVsHourly": { "highDiff": 1, "lowDiff": 0, "highMatches": false, "lowMatches": true }
}

Input

{ "stations": ["KNYC", "KMDW"], "daysBack": 1, "units": "F" }

• stations: ICAO ids, e.g. KNYC (Central Park), KMDW (Chicago Midway), KLAX, KMIA, KAUS, KDEN, KPHL. Up to 100 per run.
• date (YYYY-MM-DD) or daysBack (0–6): NWS keeps about 7 days of observations.
• units, rounding, bucketWidth, bucketOffset, bucketEdges: optional bucket labelling.
• cliLocationOverrides: rarely needed, e.g. {"KNYC": "NYC"}.

To monitor, run it every 15–60 minutes with Apify Schedules and use webhooks or integrations to send rows to Sheets, Slack or your database.

Pricing

Pay per result: $0.01 per successful station-day row. No start fee. Rows that end in an error are free. You can cap spend per run with Apify's maximum-charge setting.

Notes

• Data: US National Weather Service, api.weather.gov. It is a US Government work in the public domain. This actor is not an official NWS product.
• Only officialCLI.final = true is the settled daily value. Preliminary CLI and provisional numbers can still change.
• The CLI is usually issued shortly after midnight local standard time and is sometimes corrected later. Re-run to pick up corrections.
• The actor is polite to api.weather.gov: it sends an identifying User-Agent, makes sequential requests, and pauses between them.