Highest temperature in Miami on August 5?

Platform comparison

Market context

Miami’s 5 August maximum temperature will be set by the highest reading at Miami International Airport, with the settlement keyed to the Wunderground daily history page rather than a city-wide average. In practice, that makes the market a straight read on how the day evolves at KMIA: if early afternoon convection or sea-breeze clouds cap the peak, the winning range stays lower; if the airport stays on the sunny side of showers, the result can push up into the upper 80s or 90s Fahrenheit. With the crowd currently implying 0% for YES, the price is signalling either a stale book or an extreme disagreement with the available weather framing, so a programme that auto-reconciles forecast updates against the listed payout bands would treat this as a mispricing check rather than a directional consensus.

For context, Miami in August is normally hot and humid, with climatology heavily clustering high temperatures in the upper 80s and occasional 90-degree readings, so the relevant question is not whether it will be warm but where the daily peak lands within the settlement bands. Current forecasts around the date point to highs near 89–90°F under partly sunny skies with scattered afternoon thunderstorms, which is consistent with the upper end of the usual summer range and with comparable daily-temperature markets often concentrating around adjacent brackets rather than the extremes.[1][2][4] For a power user, that means the cleanest approach is to track the forecast distribution, map it onto the market’s discrete bins, and update orders when the probability mass shifts after each model run.

The main catalysts are routine forecast refreshes, any change in thunderstorm timing, and the final observed airport report after the settlement window closes. Wunderground’s historical day page is the source that ultimately matters, while the National Weather Service and local broadcast forecasts help identify whether cloud cover, rainfall, or a brief surge in heat will affect the day’s maximum.[2][9][12] Programmatically, this is the kind of market where an app or bot can watch hourly forecast highs, compare them with the nearest settlement range, and place conditional orders if the expected peak crosses a threshold; the key dependency is not just the headline forecast, but whether the airport records its warmest value before or after afternoon storms roll through.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Miami on August 5? 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

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.

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 Fees. 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.

Do I need to KYC for this market?

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