Highest temperature in NYC on August 6?

Platform comparison

Market context

The latest forecast update for New York City keeps August heat in the picture, but not at an extreme level: AccuWeather is showing a high of 88°F for 6 August, with nearby days mostly in the mid-to-upper 80s rather than well into the 90s.[1] A recent local forecast clip also said temperatures were running 5 to 15 degrees warmer than 24 hours earlier, with dew points in the mid-70s, which supports a hot, humid setup rather than a sharp spike to exceptional daytime maxima.[8]

That matters for reading the 0% crowd-implied price. In New York, August highs commonly sit in the 80s, and the current forecast is close to seasonal heat rather than a record challenge, which helps explain why the market is pricing a very low chance of the top temperature landing in the higher bands.[1][15] A comparable climate snapshot from nearby JFK for 6 August showed a maximum of 85°F, also consistent with a warm but not extraordinary metro-area day.[10]

Traders should watch for any late-day forecast shifts tied to cloud cover, sea-breeze effects, or convective showers, because those can trim the airport high by a few degrees even when the broader city stays muggy. The National Weather Service also had a Heat Advisory in force for the New York City area through Friday, warning of heat index values near 100 to 104°F, while actual air temperatures were expected to peak in the upper 80s to lower 90s.[11] For this market’s settlement, the key number is the LaGuardia Airport daytime maximum on Wunderground, so late updates to the airport-specific forecast matter more than headline city averages.[3]

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.

UK Frequently Asked Questions

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 Prediction Today. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.