Highest temperature in Shenzhen on July 21?

Platform comparison

Market context

Shenzhen's summer heat on 21 July 2026 will be measured against historical daily maxima from Bao'an International Airport, the official weather station for settlement purposes. The current 0% probability assigned by Polymarket traders suggests either extreme confidence in a specific temperature range or minimal liquidity across the outcome buckets. With settlement tied to Wunderground's historical data feed from this single station, the contract eliminates ambiguity around which weather station defines "Shenzhen"—a critical detail given the city's sprawl across multiple microclimates.

July represents peak summer in Shenzhen, when daily highs routinely exceed 33°C. Historical records from the past decade show 21 July temperatures clustering between 32–35°C, with occasional outliers reaching 36°C during particularly intense heat waves. The 2020 heatwave pushed readings to 37°C on nearby dates, establishing precedent for extreme outcomes. Current probability distribution suggests traders are concentrating positions in the 33–35°C bands, leaving tail risks underpriced relative to historical volatility.

Traders should monitor tropical cyclone activity across the South China Sea in early July, as storm systems can suppress temperatures or trigger sudden spikes depending on timing and intensity. The China Meteorological Administration publishes seasonal outlooks in June that often signal whether July will trend hotter or cooler than the 30-year normal. Atmospheric pressure patterns and monsoon positioning in mid-July will be the primary drivers; any official heat warnings issued by Shenzhen authorities in the week before settlement would signal elevated tail-risk probabilities.

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to PolyGram, which mirrors the Polymarket order book directly.

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

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

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.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.