Highest temperature in NYC on August 15?

Platform comparison

Market context

LaGuardia Airport’s temperature on 15 August is the key driver here, with the market settling on the highest reading in Weather Underground’s Daily Observations table rather than the Day High & Low summary. The current crowd-implied probability of 0% for YES sits well below the weather guidance, which has pointed to a warm, mostly sunny or partly cloudy day and afternoon highs around the low to mid-80s Fahrenheit, with some local sources allowing for upper-80s readings at the airport. That leaves the contract vulnerable to a higher band if the official observation log captures a late-afternoon peak.

Historical comparison suggests this kind of contract often turns on whether the airport’s actual observation clears the bracket threshold by a degree or two, rather than on broad city-wide warmth. LaGuardia can run a touch cooler or warmer than central Manhattan depending on wind off the water, cloud cover and timing of showers, so the widest gap is usually between headline forecasts and the single logged maximum that decides settlement. In that sense, a 0% market price looks more like a stale quote than a view that sub-80s weather is locked in.

The main catalysts are the hourly evolution at LaGuardia, any late showers or thunderstorms, and whether the maximum lands before the settlement cut-off at 12:00 UTC, which is 08:00 local time. Later-day warmth after that point will not matter for this contract, so traders should focus on the morning observation cycle and the published Daily Observations table, not the day’s eventual high in the summary panel.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in NYC on August 15? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Best Prediction Markets UK, which mirrors the Polymarket order book at 0% fees.

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

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'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.

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.

Do I need to KYC for this market?

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

What are the best prediction markets for UK traders in 2026?

For UKGC-regulated markets: Betfair Exchange (sports, politics) and Smarkets (sports, politics, lower commission than Betfair). For broader global event prediction: Polymarket (deepest liquidity, 0% fee, USDC settlement). For US-regulated option: Kalshi (USD, limited UK payment options). Most serious UK traders use a combination of Betfair for regulated sports and Polymarket for broader markets.