Highest temperature in Houston on August 9?

Platform comparison

Market context

Houston’s key driver is the actual **highest reading at William P. Hobby Airport** on 9 August, not the more familiar day-high figure shown elsewhere, so intraday spikes matter more than the final summary line. That matters because Wunderground’s daily observations can capture a brief afternoon peak that a snapshot forecast may miss, and this market settles from that source specifically.[3][8]

The current 0% YES price looks like an outlier against the weather setup rather than a statement that the temperature cannot move. Official and private forecasts around the date pointed to a high near **92°F** with mostly cloudy skies, a slight chance of thunderstorms, and persistent Gulf moisture, which is broadly consistent with Houston’s August climatology of mid-90s daytime highs and warm nights.[10][13][1] Weatherspark’s live observation near the event window also showed Houston already in the low 90s, leaving limited room for a much hotter print unless cloud cover broke and convection stayed away.[2][4]

For traders, the main catalysts are the timing of the warmest hour, any afternoon thunderstorm development, and whether the hourly observations at Hobby Airport are revised before the next day’s first datapoint locks the outcome under the market rules.[3] In practice, the contract is a direct USDC settlement on-chain, so the relevant risk is not a BTC or ETH macro move in the narrow sense, but broader crypto liquidity can still affect pricing if spot books, funding, or whale flows shift risk appetite during the final hours.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — sit alongside as off-chain reference points so you can see how the contract translates across regulatory and settlement regimes.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

UK Frequently Asked Questions

What does a transaction cost on Polygon?

Polygon gas is typically under $0.01 per transaction. A full trade cycle (Approve + Order + Fill) totals around $0.03 — compared to $5-50 on Ethereum mainnet.

How does UMA secure the resolution?

The UMA Optimistic Oracle uses a bond system: a proposer posts a bond, a two-hour challenge window opens. On dispute the losing side forfeits the bond — financial incentive for honest resolution.

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%.