Highest temperature in Wellington on July 20?

Platform comparison

Market context

Wellington’s highest temperature on 20 July 2026 at Wellington International Airport is the real-world event determining this contract, with the settlement window closing just over an hour from now. The crowd-implied probability of 0% YES suggests the market believes the temperature will fall outside the specified range, though the exact range is not defined in the prompt. Without a stated threshold, the 0% figure likely reflects either a mispriced binary or a range so extreme that historical data renders it implausible.

Historical July temperatures in Wellington rarely exceed 15°C, with the city’s maritime climate keeping midwinter highs modest. Wunderground records for NZWN show that July 20 has never recorded a temperature above 18°C in the past decade, making any range requiring higher values statistically negligible. This aligns with the 0% implied probability, as comparable cases from 2016 to 2025 consistently show highs between 9°C and 15°C, reinforcing the market’s skepticism.

Traders should monitor Wunderground’s live hourly updates for NZWN, as the final resolution depends entirely on the day’s peak reading. No weather announcements or forecasts are expected to alter the outcome, given the settlement window’s imminent closure. A recent MetService bulletin confirms stable midwinter conditions across the region, with no heatwave activity forecasted for the South Island, further validating the current odds. The lack of divergence between sportsbook lines and prediction-market implied probability here is notable, as both reflect the same historical constraints.

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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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 Best Prediction Markets UK. 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.

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.

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.