Highest temperature in Istanbul on July 4?

Platform comparison

Market context

The underlying real-world event is the highest temperature recorded at Istanbul Airport on 4 July 2026, with NOAA data set to determine the outcome in degrees Celsius. Polymarket prices this contract today with the "YES" option at 0% probability, implying the crowd believes the temperature will not fall into the specific range tied to that outcome. Instead, the market heavily favours 26°C at 97%, with 27°C trailing at just 2%, suggesting traders expect a standard summer peak rather than an anomaly [1].

Historical patterns frame this current probability as conservative, given Istanbul’s July 4 mean maximum typically runs between 27°C and 29°C based on long-term normals [3]. Recent ensemble forecasts from global models also point to a maximum near 25–27°C, driven by northerly flow, which aligns with the market’s 26°C frontrunner [1]. Even with Turkey experiencing its hottest July in 55 years and record national temperatures reaching 50.5°C elsewhere, Istanbul’s coastal climate rarely exceeds 90°F (32°C), rarely falling below 75°F (24°C) [2][7][9].

Traders should watch for official NOAA updates on the Istanbul Airport site, as the market cannot resolve until the first data point for 4 July is published [1]. While no immediate weather announcements are scheduled, the dependency on NOAA’s "Temp" column means any delay in data release could stall settlement until the 2026-07-04T12:00:00Z window closes. Recent reports of extreme heatwaves in southern Turkey, including 49.1°C in Kurtalan, highlight the volatility of regional conditions, though Istanbul’s microclimate remains distinct [6]. On-chain mechanics using USDC on Polygon and conditional tokens ensure transparent resolution once the metric data is confirmed.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Istanbul on July 4? 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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

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 Kalshi UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.