Highest temperature in NYC on August 3?

Platform comparison

Market context

Polymarket is pricing the LaGuardia high for 3 August as a very low-event contract, with the crowd currently assigning 0% to a top outcome and most of the visible interest sitting around the low-to-mid 80s Fahrenheit. On the exchange, traders are buying and selling conditional tokens funded in USDC on Polygon, so the quoted price is the market’s live probability view rather than a forecast from the venue itself.[1]

That 0% headline should be read against the way summer temperature markets usually cluster around nearby bins, not against a literal certainty of no heat. Polymarket’s own page shows the leading range at 82–83°F and the next at 84–85°F, both consistent with the latest model guidance it cites for New York City on the day.[1] For a late-summer New York reading, those ranges are ordinary, but the exact settlement depends on the highest recorded LaGuardia Airport temperature during the day, so a small overshoot from clouds breaking late or a brief afternoon spike can move the final bucket.[1][5]

The main catalysts are the actual hourly evolution at LaGuardia, any National Weather Service updates, and whether a thunderstorm or sea-breeze shift caps the daytime peak before the daily maximum is logged. CBS New York reported a storm threat for the NYC area on Monday 3 August, which is the sort of near-term weather wrinkle that traders watch closely because it can trim a high by a degree or two.[9] As always on Polymarket, the contract settles through on-chain ownership of the relevant conditional tokens, but the resolution source is the Wunderground history page for KLGA, so the only number that matters in the end is the recorded Fahrenheit high there.[1]

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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 UK. 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.

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 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.