Highest temperature in Shanghai on June 30?

Platform comparison

Market context

Shanghai is entering its peak plum rain season today, with heavy thunderstorms and a 90% chance of rain forecast for the Pudong area, directly suppressing the likelihood of extreme heat on June 30[7]. The crowd-implied 31% probability for a high temperature exceeding the market threshold reflects this immediate shift from dry, sunny conditions to a damp, overcast regime that has developed over the last 24 hours[7]. While sunny days in late June can spike temperatures to 36–38°C, the current wet weather pattern keeps highs hovering near 25–30°C, making the current probability a rational read of the prevailing dampness[3][5].

Historical data shows that late June in Shanghai is the rainiest period, with 2025 seeing a peak of 22 rainy days and a notable heat spike to 38°C only after the rain cleared on June 27[5]. The current 31% YES probability aligns with the typical volatility of this window, where heat spikes are possible but frequently interrupted by the rapidly increasing cloud cover that now reaches 74% of the sky[2]. Traders should watch the scheduled release of the Shanghai Meteorological Bureau’s 24-hour update tomorrow morning, which will confirm if the thunderstorm system persists or breaks to allow solar heating[7]. The primary dependency is the timing of the rain tapering; if heavy rain continues through the settlement window, the temperature will remain capped below the threshold, validating the current bearish stance on heat[3].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Shanghai on June 30? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Prediction Today, which mirrors the Polymarket order book at 0% fees.

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 Prediction Today. 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.

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.

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.