Highest temperature in Wellington on July 9?

Platform comparison

Market context

The real-world event concerns the highest temperature recorded at Wellington International Airport on 9 July 2026, measured in degrees Celsius and resolved via Wunderground data. Current crowd-implied probability for the 11°C contract sits at 0% YES, despite the 11°C line trading at nearly even odds on other platforms like Lines.com, where the contract shows $0.48 YES and $0.53 NO. This divergence suggests a potential mispricing or platform-specific liquidity gap that a programmatically oriented trader should investigate by cross-referencing live feeds.

Historical patterns for Wellington in July confirm it is the coldest month, with average highs near 13°C and lows around 7°C, while seasonal outlooks from NIWA indicate temperatures are equally likely to be near or below average, with occasional cold snaps possible under persistent high pressure. Recent observations show current temperatures at 13°C with rising pressure and southerly winds, aligning with typical winter variability rather than extreme heat. A trader approaching this market programmatically would weight these baselines heavily, treating the 0% probability as an outlier against the 11°C historical median.

Traders should monitor real-time updates from the National Weather Service and MetService for shifts in wind direction, precipitation, or pressure systems, as gale southeasterlies easing later in the day could alter the thermal profile. No major announcements are scheduled, but dependencies include Wunderground’s hourly data refresh and the resolution window closing at 12:00 UTC. A conditional order strategy might trigger only if temperatures breach 14°C, given the low baseline probability of extreme heat in mid-winter Wellington.

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 Polymarket Bot 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.

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 Polymarket Bot UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.