Highest temperature in Los Angeles on August 17?

Platform comparison

Market context

The last 24-48 hours have kept Los Angeles in a hot, dry pattern, with the National Weather Service warning of highs of 92 to 105 degrees across parts of southwest California and noting that the heat may linger into Friday in some areas[5]. For the airport station on 17 August, that leaves the market leaning on whether coastal moderation arrives in time or whether inland-style heat briefly reaches LAX, where midday conditions were already running close to 89°F in the latest Weather Underground reading[12].

That 0% crowd price sits well below the sort of outcome seen in a classic late-summer heat setup, but it is not inconsistent with a market that expects the airport to stay below the mid-90s even while the broader region runs much hotter. Recent comparable signals from Los Angeles forecasts have pointed to daily highs around the upper 80s, with August guidance commonly spanning 80°F to 91°F rather than extreme spikes[1][2]. That range matters because the market settles on the highest daily observation at Los Angeles International Airport, not the broader city high or the summary temperature.

Traders should watch whether the heat advisory language broadens, whether marine-layer clearing arrives later than expected, and how quickly afternoon sunshine builds over the basin. The key dependency is the timing of the day’s peak before the settlement window closes, since even a short-lived warm-up can set the winning range in the daily observations table[5][10][12]. If the airport stays under the low 90s, the current 0% view remains hard to dislodge; a sharper-than-forecast surge would be the main catalyst for a repricing.

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

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Prediction Today. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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%.