Highest temperature in Wellington on July 7?

Platform comparison

Market context

On 7 July 2026, the real-world event determining this market is the highest temperature recorded at Wellington International Airport in degrees Celsius. In early July, Wellington typically experiences daytime highs between 11°C and 15°C, with outcomes from 12°C to 16°C being historically meaningful[3]. The current crowd-implied probability of 0% for a YES share suggests traders believe the temperature will not exceed a specific threshold, though in prediction markets, a YES share pays out if the event occurs, while a NO share pays out if it does not. This setup anchors the market on a single, measurable weather datum sourced from Wunderground for that specific day.

Historical patterns frame how to interpret the current 0% probability. Seasonal outlooks from NIWA indicate that May to July 2026 air temperatures in the North Island are about equally likely to be near average or below average, with occasional cold snaps possible under persistent high pressure[1]. The warmest day in Wellington during July historically reaches 17.8°C, but the coldest drops to 11.1°C, making extreme heat unlikely in mid-winter[5]. Given that temperatures are most likely near average (45% chance) or below average (35% chance), the 0% probability aligns with the expectation of cool, winter conditions rather than a heatwave[1].

Traders should monitor daily weather updates and seasonal climate bulletins for shifts in pressure systems or unexpected warm spells. Current hourly data shows light rain and temperatures around 13°C with a moderate southerly breeze, reinforcing the winter cooling trend[4]. While no specific heat announcements are expected, the forecast confidence for temperatures remains medium, meaning uncertainty persists regarding whether regions will observe average or below-average warmth[1]. Any sudden rise in pressure or a shift to northerly winds could act as a catalyst, though current conditions strongly favour the below-average temperature range.

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

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