Highest temperature in Beijing on June 28?

Platform comparison

Market context

The real-world event driving this market is the peak daily temperature recorded at Beijing Capital International Airport on 28 June 2026, measured in degrees Celsius. With the current crowd-implied probability of 0% for a "YES" outcome, the market suggests traders believe the temperature will fall outside the specific range being bet on, likely because historical data points to a much lower or higher threshold than anticipated.

Historical precedents frame this probability starkly: in June 2023, Beijing shattered records with a peak of 41.1°C, the hottest June day in over 60 years[1][2]. However, typical June averages for the region hover between 28°C and 33°C, rarely exceeding 36°C[3][4]. The 0% probability implies the market expects the temperature to stay within the normal band, avoiding the extreme 41°C outlier seen in recent years, or that the specific range offered is simply too narrow to capture the likely 30–34°C outcome.

Traders approaching this programmatically should monitor real-time weather feeds from Wunderground and cross-reference with AccuWeather forecasts for June 2026, which predict daily highs between 25°C and 34°C[6]. Key catalysts include the arrival of heatwaves from northern China, similar to the 2023 event that drove temperatures past 41°C[1]. A sudden shift in wind patterns or cloud cover could act as a dependency, altering the peak temperature significantly; therefore, automated bots should trigger conditional orders based on hourly temperature deviations exceeding 2°C from the 30°C baseline.

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

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.

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 Fees 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.