A heat dome is parked over Texas — a stalled upper-level ridge trapping hot air from El Paso to Beaumont. Daily highs are running 8–15°F above seasonal normals. Below: what the live prediction markets say about how hot each major Texas city will get today, when forecasters expect the dome to break, and (if you've never traded one of these before) the absolute-beginner playbook for following along.
Live temperature odds — 4 Texas cities
Each widget below pulls live YES prices from Polymarket's daily high-temperature market for that city. Bars show the implied probability the official National Weather Service high lands in each bracket today. They re-price as the forecast and live observations change — usually the fastest public signal of when traders expect the heat dome to break.
Tip: cross-reference each city's prices with its NWS Austin · NWS Houston · NWS Dallas · NWS San Antonio forecast. The market is usually within 1–2°F of the NWS forecast; gaps are where edge lives.
What is a heat dome, exactly?
A heat dome is a strong, slow-moving area of high pressure aloft (around 18,000–25,000 feet) that acts like a lid. It compresses and warms the air column underneath it, shuts down convection (storms can't punch through), and lets the ground bake. Once the soil dries out, less of the sun's energy goes into evaporating water and more goes into heating the air — which strengthens the ridge. That's the self-reinforcing feedback loop that turns a one-week heat wave into a multi-week event.
When will the Texas heat dome end?
There are three signals worth watching, in order:
- The NWS Climate Prediction Center 6–10 day and 8–14 day outlooks. Updated daily. When the "above-normal" probability over Texas drops below ~60%, the ridge is forecast to weaken.
- The next cold front in the Plains. Heat domes break when the upper-level pattern shifts and a trough digs into the central US, pushing a front south. Watch the 500mb pattern on any weather model dashboard.
- Live Polymarket and Kalshi prices. When the probabilities on the lower temperature brackets for the next 3–5 days start rising, the market is pricing in the break before it's confirmed in the headlines.
Why is it so hot in Texas right now?
Three factors stacking on top of each other: a persistent upper-level ridge (the dome itself), unusually warm Gulf of Mexico SSTs pushing humidity inland, and a La Niña-leaning Pacific pattern that has suppressed Plains storm tracks. Houston gets hammered on heat index because of Gulf moisture; Austin, Dallas, and San Antonio see the highest absolute temperatures because they're farther inland and drier.
Brand new to prediction markets? Start here
Daily weather markets are the gentlest on-ramp in the entire space. Why:
- One concrete question. "What is the high temperature in Austin today?" There's no judgment call on resolution — the NWS publishes the number.
- Short time window. Markets resolve the same day. You learn the loop quickly instead of waiting months for an election to settle.
- Small ticket sizes. You can place a $5 trade and learn the mechanics.
- Two regulated US venues. Kalshi (CFTC-regulated) and Polymarket (US entity) both list these contracts. Both are legal in Texas for 21+.
Beginner workflow: pull up the NWS forecast for your city, open the corresponding daily market on Kalshi or Polymarket, find the bracket your forecast falls in, and place a small YES position. Watch how the price moves through the day as observations come in. Resolve. Repeat.
Where to trade Texas heat markets
The CFTC-regulated US exchange. Daily high-temperature contracts for Austin, Houston, Dallas, and San Antonio, plus monthly averages and ERCOT-adjacent contracts during grid stress.
Daily high-temperature brackets with surprising volume — Austin and Houston regularly clear $30K–$150K per day. The widgets above stream live from Polymarket's gamma API.
Heat safety + ERCOT grid watch
Sustained triple-digit highs across all four major metros push ERCOT toward record peak demand. Conservation notices, emergency alerts, and rotating outage warnings all become live possibilities. Keep ERCOT's grid conditions dashboard open during peak hours (3–8pm). For heat-illness prevention, the CDC and Texas DSHS recommend avoiding outdoor exertion between 11am and 7pm, hydrating constantly, and checking on neighbors — especially older adults and anyone without reliable AC.
More: Full Texas weather markets playbook · All Texas weather contracts · Are these legal in Texas?