Highest temperature in Wellington on July 31?

Platform comparison

Market context

Wellington’s late-July high for 31 July is shaping up to be a **low-teen Celsius** outcome, with the main forecast sets clustering close to 9–14°C rather than anything warmer. MetService’s Wellington forecast sits around 9°C, the Met Office shows a 9°C maximum for Wellington with cloudy, windy conditions, while AccuWeather’s monthly page points to a historical average high of about 12°C for 31 July; by contrast, temperatures.com is more optimistic, calling for a 53°F high, roughly 11.7°C.[5][2][1] For a contract that resolves to the highest temperature at Wellington Intl Airport Station on the day, that spread matters: the market is not pricing an extreme, but a fairly ordinary winter ceiling, with the crowd-implied 0% YES suggesting the contract is being treated as an outside-the-range outcome rather than a base case.

Historically, Wellington’s July climatology supports that scepticism. WeatherSpark puts average July daytime highs around 53°F, or about 11.7°C, and notes highs rarely fall outside roughly 48–57°F, which keeps most realistic outcomes inside the same narrow band the forecasts already suggest.[12] With the settlement source tied to Wunderground’s Wellington Intl Airport Station history page, the key read-through is whether the airport’s official daily maximum lands in one of the listed temperature bands, not whether the city feels briefly milder elsewhere.[17] In prediction-market terms, there is a meaningful gap between the 0% YES crowd price and the forecast consensus: the broader weather model set is anchored near the low teens, while sportsbook-style certainty would normally track the same range unless a late shift in wind or rain materially changes the day’s peak.

The main catalysts before settlement are the final overnight model updates, any late Wellington-specific wind or rain changes, and the airport station’s actual midday temperature trace, which can move more than the citywide forecast headline. Current guidance still leans showery and windy rather than warm, with temperatures.com flagging patchy rain nearby and a 59% precipitation chance, while the Met Office also keeps precipitation in the picture alongside gusty southerlies.[1][5] Because the market resolves on the *highest recorded temperature* for the day at the airport station, traders should watch not only the forecast maximum but also the timing of any brief clearing or föhn-like lift that could allow a short-lived spike above the expected band.[17][3]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Wellington on July 31? 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

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. 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 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.