Highest temperature in Wellington on August 18?

Platform comparison

Market context

Wellington’s 18 August reading points to a cool, windy day, with most local forecasts clustered around a high of roughly 9–11°C and some services carrying only a modest chance of a brief rise above that. That sits comfortably with the current 0% YES implied probability, and there is no obvious sportsbook-style price to compare it with for this specific contract.

Historically, August highs in Wellington are usually in the single digits to low teens, so a settlement band centred on around 10°C is the baseline rather than an outlier. Forecast products are also fairly tight here: AccuWeather points to a 54°F high with strong southerlies and rain, while WeatherWatch and other local forecasts show about 11°C with showers and brisk winds, which supports a lower-temperature outcome rather than a warm spike.

The main catalyst is the midday UTC settlement cut-off, because the market resolves off the highest temperature in Weather Underground’s Daily Observations table at Wellington Intl Airport rather than the summary day high. Traders will therefore watch the airport station’s hourly progression, especially any brief midday lift before 12:00 UTC, plus wind, rain, and cloud timing that could cap the maximum despite any later warming after the window closes.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Wellington on August 18? 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

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.

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