Highest temperature in Houston on August 9?

Platform comparison

Market context

Polymarket is pricing the **92–93°F** band at effectively **100%**, so the contract is treating an August Houston high near the low 90s as near-certain in USDC terms on Polygon. With the market already fully concentrated in one bucket, the practical question for holders is not whether August heat is plausible, but whether Hobby Airport’s final Daily Observations maximum lands inside that band once Weather Underground closes the day’s data.

That pricing fits Houston’s late-summer climatology. National Weather Service climate normals for Houston/Hobby put the average August maximum around **94°F**, with record highs far above that, so a final reading in the low 90s is consistent with a typical warm, humid Gulf Coast day rather than an outlier. Current public forecasts around the event also pointed to highs around **92°F** and a low near **79°F**, which supports the market’s narrow expectation rather than a wide distribution of outcomes.[8][9][12]

For traders, the main catalysts are straightforward: the afternoon high itself, any thunderstorm timing that can cap temperatures early, and the publication of the final Weather Underground Daily Observations entry for KHOU, which controls settlement here rather than the summary “Day High & Low” figure. Because Polymarket updates continuously as conditional-token prices move, the only meaningful late shift would come from an observation revisal before the next day’s first datapoint is posted, not from broader Houston weather chatter or forecasts after the fact.[4][19]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

UK Frequently Asked Questions

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.