Highest temperature in Wellington on August 17?

Platform comparison

Market context

Wellington International Airport will record its highest temperature on 17 August 2026, with the market currently pricing all temperature ranges at 0% implied probability—a technical artefact reflecting the settlement window closure date being identical to the event date itself. The resolution will draw from Weather Underground's Daily Observations table rather than the summary Day High & Low section, a distinction that occasionally produces material differences when station equipment cycles or reporting protocols shift mid-day.

August represents Wellington's late winter period, when daily highs typically range between 12–15°C, though the city's exposed location and variable wind patterns create volatility. Historical data from the past decade shows occasional spikes to 18–20°C on clear, northerly wind days, whilst readings below 10°C occur roughly 20% of the time. The 0% crowd probability reflects the market's structural constraint: settlement occurs at noon on the event day, leaving no post-event trading window and creating a liquidity desert for real-time price discovery.

Traders monitoring this contract should track MetService and NIWA forecasts released in the week preceding 17 August, particularly any high-pressure systems tracking towards the lower North Island. Southerly outbreaks or frontal systems arriving that morning would suppress temperatures materially. The specific reliance on Wunderground's Wellington Airport station data means equipment maintenance schedules or sensor recalibration notices from that facility warrant attention, as such events have occasionally caused historical data revisions that affect settlement interpretation.

Methodology

We track Highest temperature in Wellington on August 17? 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

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.

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.

Do I need to KYC for this market?

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

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.