Highest temperature in Miami on August 13?

Platform comparison

Market context

Miami International Airport's daily temperature peak on 13 August 2026 will be measured against historical August conditions in South Florida, where afternoon highs typically range between 88–92°F. The market resolves using Weather Underground's Daily Observations table rather than the summary Day High & Low section, a distinction that matters when multiple stations report slightly different readings or when intraday revisions occur. This specification reduces ambiguity but requires traders to understand that the official record may differ from casual weather app displays.

August represents Miami's hottest month climatologically, with the National Weather Service recording a median high of 90°F and extremes occasionally exceeding 95°F during heat domes or when tropical systems approach. The 0% crowd probability suggests traders are either confident the market's temperature bands exclude realistic outcomes, or the current odds structure on competing platforms (Polymarket's decimal format versus Kalshi's binary structure) has created pricing inefficiencies. Betfair and Smarkets typically offer tighter spreads on weather markets through their exchange models, though liquidity on niche US weather events remains limited compared to major political or sports contracts.

Traders should monitor the Atlantic hurricane season's trajectory through early August, as tropical moisture and wind patterns significantly influence daily maxima. The National Hurricane Center's forecasts issued in late July and early August will be critical; even a distant system can suppress afternoon temperatures through cloud cover and convection. Additionally, any equipment maintenance at Miami Intl Airport's weather station in the weeks preceding 13 August could affect data continuity, though such events are typically announced in advance through NOAA channels.

Methodology

We read Highest temperature in Miami on August 13? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live mid is the canonical probability; the side-by-side columns benchmark fees, KYC, settlement currency and deposit rails so you can choose the venue that fits your jurisdiction and trade size.

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.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Robinhood Prediction Markets has a different geo footprint and routes to Polymarket's order book at 0% fees.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Robinhood Prediction Markets 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.