Highest temperature in NYC on August 8?

Platform comparison

Market context

New York City’s highest temperature on 8 August was effectively a LaGuardia Airport call, and the market has already priced it as a certainty: Polymarket shows **90–91°F at 100% implied probability**, with the only visible alternative, **81°F or below, below 1%**. That leaves little room between prediction-market pricing and the contract’s own resolution standard, which keys off the Weather Underground **Daily Observations** for **KLGA** rather than any headline “Day High & Low” summary. Robinhood’s matching event is framed the same way, using the LaGuardia Airport Station reading as the underlying high.[4][10]

Historically, August highs at LaGuardia often sit in the upper 80s to low 90s, so a 90–91°F resolution is not unusual for early August in New York. AccuWeather’s August calendar for New York shows 89°F for 8 August and 90°F for 9 August, while WeatherSpark’s latest report for KLGA on the afternoon of 8 August recorded 89.1°F, which is consistent with the market’s top bin and explains why the contract has converged so hard on that outcome.[1][2] The key market read-through is that the crowd is not pricing a heat extreme; it is pricing a fairly ordinary late-summer warm day landing in the contract’s preferred range.[4]

For traders, the only meaningful catalyst is the final station observation flow and any retrospective revision before Weather Underground closes the record for the following date. The market rules say later alterations do not count once the first datapoint for the next date is published, so the practical dependency is on the timing and stability of KLGA’s Daily Observations table, not on forecasts or broadcaster graphics.[4] There is no meaningful sportsbook-vs-market spread to arb here: the crowd consensus and the listed contract line are already aligned at the top outcome, so any divergence would have to come from a late data correction rather than from weather-model surprise.[4]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in NYC on August 8? 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

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.

Do I need to KYC for this market?

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

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.