Highest temperature in Wellington on August 1?

Platform comparison

Market context

Wellington’s highest temperature on 1 August will be set by the reading at Wellington Intl Airport, with the contract resolving to the range containing that day’s maximum in degrees Celsius. August is normally one of Wellington’s cooler months: long-run climate guides put average daytime highs around 12°C to 13°C, so the market is really about a modest winter warm-up rather than any genuine heat event.[1][12][17]

That matters for the current **0% YES** crowd view, because the upside is constrained by climatology even though rare late-winter spikes can occur. Historical summaries for Wellington show an August record high of 18°C in 2017 in one climate dataset, while broader city records reach far higher in summer, underscoring how unusual a strong August maximum would be.[17][16] In practical terms, a 0% implied price looks consistent with traders treating a higher Celsius band as a tail outcome, not a base case, and there is no clear evidence here of a meaningful disagreement with weather-model or climatology-based expectations.[1][12][17]

The main catalyst is the actual airport observation through the settlement window, not a policy announcement or scheduled release; for temperature contracts, the key dependency is whether Wellington gets a brief sunshine break, a föhn-like northerly, or persistent cloud and rain suppressing the day’s peak. Wellington’s August weather is typically variable but cool, with average highs around 12°C and fairly stable conditions across the month, so even a small shift in wind and cloud cover can move the maximum into a different range.[3][7][13] Traders will usually watch local forecasts, hourly updates and airport observations rather than national headlines, because the contract settles on the single highest temperature recorded at the specified station.[14][15]

Sources: 1 · 2 · 3 · 4 · 5

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

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 Best Prediction Markets UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Best Prediction Markets UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.