The weather model that surfaces where forecasts and markets diverge
A second-opinion temperature model across 17 US airports, live on your iPhone. Real-time NOAA observations, fair value per Kalshi bucket, and a full daily-updated accuracy log so you can judge the model before you trust it.
iPhone · iOS 17+ · 7-day free trial on Pro · Subscription auto-renews at the price shown unless cancelled at least 24 hours before the period ends.
See it work
30 seconds of the app, unedited.
Signals · Kalshi Ladder · Intraday Chart · Accuracy
How the model works
We don't predict the weather from scratch. We predict where NOAA gets it wrong.
NOAA forecast + live METARs
Every 10 minutes we pull NOAA's gridded forecast and real-time METAR observations from the airport station itself. The raw ingredients.
Adaptive bias correction
A per-city, per-sky-condition model learns how NOAA systematically over- or under-forecasts each station. Applied to tonight's forecast, the corrected prediction historically lands closer to the CLI.
Fair value per bucket
We map the corrected prediction to every Kalshi temperature bucket and publish a fair-value probability. When market price disagrees, you see the edge — then you decide.
Model performance · tracked daily
Measured against the official NWS CLI daily-high settlement. Headline MAE and NOAA comparison are computed 6+ hours before peak, when the markets are actively pricing. The at-peak line reflects predictions made after the high has likely already occurred. Full per-city breakdown and the calibration table live in the app's Accuracy tab — we show all the misses, not just the wins.
What Sardine is
A data analytics tool. A second opinion to the NOAA forecast. A way to see when a Kalshi market price looks off versus the observed weather data.
What it isn't
A broker. A trading platform. Financial advice. A recommendation engine. Sardine publishes numbers. You decide what to do with them.
Questions
The ones that come up most. Missing something? Ask.
How is this different from the NOAA forecast?
We take NOAA's gridded forecast as the starting point, then apply a per-city adaptive correction based on how NOAA has systematically erred for that specific station recently. Over the tracked window, Sardine's headline MAE is 2.18°F vs NOAA's 2.80°F — about 22% tighter — and 64% of predictions land within ±1°F of the CLI settlement when evaluated at peak.
What if the model is wrong?
It's wrong sometimes — every forecast is. We publish full accuracy in the Accuracy tab, per city and per time-to-peak band. You see misses the same day they happen, no curation. If a city has a track record you don't trust, trade a different one.
Do I need a Kalshi account to use this?
No. Sardine is a data tool — the Kalshi bucket prices are shown for reference so you can see where market pricing disagrees with the model. If you want to trade, each bucket row links directly to the Kalshi market. We don't route orders, hold funds, or take a cut.
What exactly do I get with Pro?
Real-time model output (no 10-minute delay), edge and fair-value per bucket for every city, confidence tiers that flag when the model is most reliable, per-city historical performance, and direct tap-to-open Kalshi links. Free tier shows NOAA + current obs + one fully unlocked demo city so you can see what the experience is like before paying.
Is it just for traders?
Mostly, yes — the pricing reflects that. If you're someone who tracks the peak daily temperature (utility operators, logistics, HVAC ops, anyone long-gamma on heat), the 1.10°F MAE at-peak forecast is useful even if you never touch a Kalshi market. But trader is the core user.
One plan, one price
Start free. Try Pro for 7 days. Cancel anytime in iOS Settings.
Free
See what the model sees.
- NOAA forecast + current temp
- Kalshi bucket prices
- Houston unlocked as demo city
- 10-minute data delay
Pro
or $249.99/year · save 41%
Full model. Real-time. Every city.
- Real-time model output — no 10-minute delay
- Edge %, fair value, cost, ROI for every city
- Confidence tiers and per-city model performance
- Direct links to Kalshi contracts
- 30-day accuracy history, tracked daily
- Cancel anytime in iOS Settings
Subscription auto-renews at the price shown unless cancelled at least 24 hours before the period ends. Your Apple ID is charged on confirmation. Manage or cancel anytime in iOS Settings → Apple ID → Subscriptions.
The edge fits in your pocket.
The market misprice happens before the close. Be ready for it.
7-day free trial · cancel anytime · subscription auto-renews at $34.99/mo