Highest temperature in Shanghai on August 4?

Platform comparison

Market context

Shanghai’s midday heat is likely to be the main driver of the reading, because the market settles on the **highest temperature recorded at Shanghai Pudong International Airport** on 4 August rather than an average or citywide figure. Forecasts for Shanghai this August cluster in the low- to mid-30s Celsius, with daily highs around 32°C to 34°C and warm nights, which makes a settlement in the upper end of the contract’s range more plausible than an outlier cool print.[1][3][7][10][15]

The current **0% YES** implied probability looks mispriced only if the market is using a narrow temperature band that excludes the likely forecast outcome; on the weather pages, 4 August is repeatedly shown around 33°C to 34°C, and several August outlooks place Shanghai’s daytime maximum near 31°C to 32°C, still consistent with a summer peak above the common low-30s benchmark.[2][4][8][18] The key historical frame is simple: early August in Shanghai is typically hot, humid, and often sticky enough for temperatures to reach the low or mid-30s, so traders should read the contract as a question about whether the airport station prints a normal summer high or something closer to the upper edge of recent guidance.[4][7][8][13]

For catalysts, the main inputs are the short-range weather model updates and whether a passing rain band or typhoon-related cloud cover caps the daytime maximum. Shanghai’s August climatology includes meaningful rainfall and some storm risk, so a last-minute forecast revision can matter more than the broader monthly average; the market resolves on Wunderground’s airport-station history, so a brief afternoon spike at Pudong is what counts.[3][7][13] Since settlement is in USDC on-chain, the market is likely to track the usual crypto microstructure only indirectly, but BTC and ETH risk appetite can still affect liquidity, bid depth and how quickly price adjusts when fresh weather forecasts hit.[3][7]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reads Highest temperature in Shanghai on August 4? on-chain. Polymarket's quote comes directly from the Polygon order book — the only comparable venue with on-chain settlement. Kalshi (USD, off-chain), Betfair (GBP/EUR, off-chain) and Manifold (play-money) are listed alongside for venue context. Every CTA routes to BTC Prediction, which mirrors the Polymarket order book directly.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

FAQ

Why USDC and not ETH or USDT?

USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.

What does a transaction cost on Polygon?

Polygon gas is typically under $0.01 per transaction. A full trade cycle (Approve + Order + Fill) totals around $0.03 — compared to $5-50 on Ethereum mainnet.

How volatile are crypto prediction markets?

Crypto markets react to spot prices — a 5% BTC move typically shifts a "BTC above X by date" market 10-20%. Polymarket crypto market liquidity is usually six-figure USD, sufficient for active trading.

Which crypto markets exist on Polymarket?

Currently active markets include BTC/ETH/SOL price targets, halving dates, ETF approvals, hard-fork outcomes and Layer-2 TVL thresholds. The list updates weekly; biggest volume sits on BTC and ETH price forecasts.

Are crypto prediction markets taxable in the US?

In the US, prediction market gains are typically treated as ordinary income or short-term capital gains depending on holding period. Consult a tax professional for your specific situation — we cannot provide tax advice.