Highest temperature in Houston on July 15?

Platform comparison

Market context

On 15 July 2026, the William P. Hobby Airport station in Houston will record its peak daily temperature in degrees Fahrenheit, a figure that will settle a prediction market comparing how different platforms price extreme weather. The crowd currently assigns 0% probability to the YES outcome, yet Polymarket’s frontrunner suggests an 84–85°F range at 43% implied probability, highlighting a stark divergence from books like Kalshi or Betfair that often use decimal odds rather than raw probabilities and impose stricter KYC gates.

Historical July highs in Houston frequently reach near 98°F, with this week’s forecast consistently hovering around that mark, making the 84–85°F range an outlier unless a rare cooling front intervenes [1]. Such discrepancies between platforms often stem from fee structures—Polymarket’s lower fees attract speculative liquidity that can skew probabilities compared to Smarkets’ higher-cost, regulated model—while the 0% YES reading may reflect a binary misinterpretation of the market’s range-based resolution rather than genuine disbelief in any heat event.

Traders should monitor the National Weather Service’s daily high-temperature forecasts for Houston and real-time updates from Wunderground, the official resolution source, as any sudden shift in cloud cover or wind patterns could alter the peak reading [2]. Unlike Betfair’s market-making depth, Polymarket’s order-book style may amplify volatility if new data arrives late on 15 July, and the settlement window ending at 12:00:00Z means the final temperature must be confirmed before that deadline, leaving little room for post-cutoff adjustments.

Sources: 1 · 2

Methodology

This page compares Highest temperature in Houston on July 15? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Robinhood Prediction Markets, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

Are all these platforms regulated?

No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Robinhood Prediction Markets offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.