Highest temperature in Wellington on July 18?

Platform comparison

Market context

Wellington's maximum temperature on 18 July 2026 will be recorded at the airport weather station and resolved against Wunderground's historical data archive. July sits within Wellington's winter season, when daily highs typically range between 8–13°C, though the specific outcome depends on synoptic patterns—frontal systems, ridge positioning, and Southern Ocean influence—that remain uncertain at this lead time.

Historical July data from Wellington Airport shows considerable day-to-day variability. The station has recorded maxima as low as 6°C and as high as 17°C during the month across different years, with median values clustering around 10–11°C. This spread reflects Wellington's exposure to competing air masses; southerly outbreaks can suppress temperatures sharply, whilst northerly flows ahead of frontal systems occasionally push readings into the mid-teens. The 0% crowd probability suggests traders are either awaiting clearer meteorological guidance or treating this as a calibration exercise given the two-year forecast horizon.

For programmatic monitoring, the key dependency is the Wunderground archive's update schedule and data consistency at NZWN (Wellington International Airport's WMO code). Traders building conditional orders or automated resolution checks should verify the site's historical data lag—typically 24–48 hours—and confirm temperature unit settings before deployment. New Zealand MetService publishes extended outlooks roughly 10 days ahead; watching their seasonal and monthly forecasts from June 2026 onwards will signal whether anomalous warmth or cold is expected for that specific week.

Methodology

We track Highest temperature in Wellington on July 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 Fees trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.