Highest temperature in Istanbul on July 9?

Platform comparison

Market context

The underlying event is the peak daytime temperature recorded at Istanbul Airport on 9 July 2026, a date that falls squarely within Turkey’s driest and hottest month. Long-term averages for Istanbul in July show daytime maximums of 27°C with 12 hours of sunshine, while regional data indicates most of Turkey experiences intense heat exceeding 30°C during this period[3][4]. Historical patterns for the first ten days of July in Istanbul show average highs of 27.2°C, suggesting that a 25°C outcome is plausible but slightly below the typical mean, whereas a 29°C reading would represent a significant heat spike[6].

Current crowd-implied probability of 0% for a specific high-temperature range on Polymarket appears to diverge sharply from the platform’s own frontrunner data, which assigns a 48% chance to 25°C and 36% to 24°C, indicating the market is actively pricing moderate heat rather than dismissing it entirely[1]. This contrasts with the July 7 market where 27°C was priced at 100%, highlighting how quickly sentiment shifts between consecutive days in volatile summer weather[2]. Traders should monitor the NOAA time-series updates for LTFM (Istanbul Airport) as the settlement window closes, specifically watching for the "Switch to Metric Units" toggle to confirm the °C reading under the "Temp" column, as any delay in the first data point for 9 July could postpone resolution[1]. Recent forecast uncertainty across a wide degree range for Istanbul’s July peak temperatures, similar to the 46.5% pricing for 29°C on the 8 July contract, suggests that forecast models remain fluid and that real-time data will be the definitive catalyst[5].

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.

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

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.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.