Highest temperature in NYC on August 9?

Platform comparison

Market context

The key real-world event is the highest temperature recorded at LaGuardia Airport on 9 August, and the contract resolves from Weather Underground’s Daily Observations rather than the summary day-high figure. On the current board, the crowd is heavily concentrated in the **90–91°F** bucket at **73%**, with **92–93°F** at **20%** and only a small tail in cooler or hotter bins, which points to a market that is already pricing in a warm but not exceptional afternoon. That sits broadly in line with public forecast guidance: Polymarket’s own market text cites National Weather Service and AccuWeather guidance around a near-90°F high, while AccuWeather’s monthly page shows **90°F** for 9 August in New York and **91°F** the following day.[1][4]

For historical framing, late-summer highs in New York City commonly cluster in the upper 80s to around 90°F, so the current pricing is close to a climatological central case rather than a genuine heat-wave extreme.[12] Recent comparable hot spells matter more for understanding tail risk than for setting the base rate: New York has reached **100°F** on a daily basis during the 2026 North American heat wave, but those were standout conditions, not the norm.[11] The main cross-platform divergence is that the prediction market is effectively treating 90–91°F as the modal outcome, while sportsbook-style weather products and analyst consensus have tended to anchor nearer 90°F without much conviction about a breakout into the mid-90s.[1][4]

Traders should watch the overnight and morning Weather Underground updates for KLGA, because the settlement source can change if late observations are revised before the next day’s first datapoint is published.[1] The most relevant catalysts are any shift in sea-breeze timing, cloud cover, or convective development, since those can move the airport’s peak by a degree or two even when the broader city forecast looks stable; the NWS New York office was still issuing routine updated forecast products for the area on the morning of 9 August.[14] With the contract already implying a very low chance of a colder-than-expected outcome, the practical risk on the board is whether the official observation lands just below or just above 91°F, rather than any large repricing into the mid-90s.[1][9]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in NYC on August 9? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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 vs Polymarket. 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 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.

Do I need to KYC for this market?

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