Highest temperature in NYC on August 9?

Platform comparison

Market context

The relevant real-world event is the highest recorded temperature at LaGuardia Airport on 9 August 2026, measured from Weather Underground’s **Daily Observations** table rather than the summary high/low box. That matters for programmatic tracking because the settlement source is a station-specific intraday maximum, so a trader building a bot should poll the KLGA daily history page, watch for late uploads, and treat the first reading for 10 August as the practical cutoff for any revisions.

The current 0% YES implies the crowd does not expect the observed maximum to land in the market’s target band, but the historical frame is straightforward: late-summer New York City highs often sit in the 80s, while stronger heat events can push LaGuardia into the 90s. On 9 August 2026, Weather Underground’s live Manhattan data showed KLGA at 88.0°F with a 6-hour high of 89.1°F by 1:51 pm local time, and AccuWeather’s daily outlook for New York listed 90°F for the date, which is consistent with a hot but not extreme day.[1][2]

For catalysts, the key inputs are the afternoon progression of the boundary layer, any sea-breeze timing, and whether a weak front arrives early enough to cap the peak. The National Weather Service’s New York forecast page showed Central Park at 83°F with the latest update at 8:51 pm EDT, which is useful as a cross-check on the broader metro heat pattern even though it is not the settlement source; for an automated workflow, the highest-value trigger is the next Weather Underground observation update, followed by any revision window before the 10 August datapoint appears.[5][10]

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

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 Kalshi Fees. 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.

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi Fees trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.