Highest temperature in NYC on August 23?

Platform comparison

Market context

The market is pricing the day’s eventual high at 0% YES, so the consensus is effectively that LaGuardia will stay below every listed settlement band, with the value debate concentrated on whether a late-afternoon rebound can still lift the maximum into a higher bracket. At 0%, the favourite is the lowest temperature range by a wide margin, and any contrarian case rests on the chance that the morning cloud and shower activity clears fast enough for a stronger warm-up later in the day.

That framing looks plausible against the comparable backdrop: LaGuardia opened the day around 71F with overcast skies, light rain, and very moist air, while the forecast called for showers and thunderstorms early, then some sunshine later, with highs in the lower 80s. Current August expectations for New York have centred on highs mostly in the upper 70s to low 80s, so the market’s zero-implied chance for a decisive upside surprise reflects a view that the day’s ceiling remains ordinary rather than hot. The underdog angle is a brief convective burst or faster-than-expected clearing, but the consensus still sits around a middling summer outcome rather than an extreme.

Traders should watch the timing of any thunderstorm line, cloud break-up, and the airport’s actual NOAA station readings through the afternoon, because the market resolves on the single highest observed “Temp” value at KLGA. Morning precipitation and cumulonimbus can cap the early range, but if skies clear and winds turn more southerly, the high can still print later than expected. The key dependency is the station’s observed trace after the settlement window, since the market cannot resolve until the next day’s data point is available.

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.

FAQ

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.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.