Live NWS forecast verification

Every NWS revision.
Every station. At issuance.

Forecast accuracy data for the 20 stations Kalshi settles on — verified against ASOS/AWOS, served fresh every 5 minutes.

Get your API key See live data

See live data

Updated every 5 min
·
20 stations
·
ASOS / AWOS verified
·
90-day rolling window

Which stations run hot vs cold vs the forecast?

Cold bias (under-predicted)Hot bias

KMDW

-5.8°

KOKC

-2.2°

KMSY

-1.4°

KNYC

+2.2°

KDEN

+1.1°

KDFW

+0.9°

GET /v1/accuracy/by-station?sort=biasView all stations

How it works

Capture, verify, serve.

Capture revisions at issuance

We ingest every NWS forecast update for 20 Kalshi market stations, every 5 minutes. Every revision tracked with issuance timestamp.

Compare to verified observations

Each forecast is paired with the actual ASOS/AWOS temperature observation — the same source NWS uses, and the same data that settles temperature contracts.

Serve metrics by station, lead time, and bucket

Bias, MAE, std dev, and correction factors delivered via REST API. Filter by station, lead time window, or temperature bucket.

cURL

curl -s "https://api.deltadaemon.com/api/v1/accuracy/by-station/KBOS?days=90" | jq .data

{
  "city_name": "Boston",
  "sample_size": 47,
  "station_id": "KBOS",
  "stats": {
    "verification_pairs": 47,
    "unique_days": 4,
    "mean_error": 1.19,
    "std_dev": 3.11,
    "mae": 2.52,
    "rmse": 3.3,
    "abs_error_p50": 2,
    "abs_error_p90": 5.8,
    "abs_error_p95": 6.5
  }
}

The API

Query forecast accuracy by station, lead time, or date.

Free up to 100 calls/day on 5 stations. $10/mo for all 20 stations and 10k calls/day.

Get your API key Read the docs

Read the docs

Free tier · no credit card required