Highest temperature in Miami on August 24?

Platform comparison

Market context

Miami’s high at the airport is usually driven by the timing of afternoon convection as much as by the morning start, and the NOAA hourly series at KMIA is the settlement source here, not a city-wide forecast or a nearby station. The market is about the single highest observed temperature on 24 August, so the relevant comparison is to prior late-August heat in Miami rather than to the day’s average; in recent climate reports for Miami, highs in the low to mid-90s F have been commonplace, with showers and storms often developing later in the day.[1][2]

The current 0% yes price looks more like a platform artefact than a weather statement, because these contracts often move only when fresh hourly observations or forecast shifts arrive. Traders usually watch the NOAA hourly page for KMIA, the National Weather Service Miami forecast discussion, and any storm timing that could cap the daytime maximum; on a hot, humid South Florida day, an early thunderstorm can leave the eventual high lower than the morning trend suggested, while delayed storms can preserve a mid-90s F print.[1][2][4]

On venue choice, Polymarket’s crowd probability format makes the market easy to read directly, whereas Kalshi-style pricing is typically quoted in cents and Betfair or Smarkets in decimal odds, which can make the same weather view look different across books. The practical differences also sit in fees and access: Betfair and Smarkets usually charge explicit commissions, while regulated US venues add KYC and residency constraints that can exclude some traders even when the weather logic is identical.[1][4]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Miami on August 24? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Polymarket Alternative, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

Are all these platforms regulated?

No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Polymarket Alternative offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.