Highest temperature in Wellington on July 20?

Platform comparison

Market context

Wellington’s highest temperature on 20 July 2026 at Wellington International Airport is the real-world event determining this contract’s outcome, with the crowd currently pricing a YES resolution at 0%. On Polymarket, traders are using USDC on the Polygon network to buy conditional tokens tied to specific temperature ranges, locking in exposure until the settlement window closes at 12:00 UTC on the settlement date. The market resolves strictly to the Celsius range containing the day’s peak reading, sourced from Wunderground’s historical daily data for NZWN.

Historically, mid-July in Wellington rarely exceeds 15°C, with BBC Weather showing today’s current maximum at 15°C amid strong south-south-westerly winds and 24 mph gusts [2]. MetService New Zealand confirms that daily maximums at NZWN in July typically cluster between 10°C and 16°C, making extreme highs statistically improbable and justifying the near-zero YES probability [1]. No recent July 2025 or 2024 records in Wellington breached 18°C, reinforcing the market’s conservative stance.

Traders should monitor MetService’s 72-hour forecast updates and any sudden shifts in wind direction, as a switch to northerly flow could trigger a rapid temperature spike. While Wunderground is the official resolution source, discrepancies between its data and MetService’s official records could delay settlement, so watching for real-time station alerts is critical. No major weather announcements have been issued yet, but the dependency on a single data feed means traders must verify Wunderground’s live NZWN feed before expiry to avoid resolution ambiguity.

Sources: 1 · 2

Methodology

This page reviews Highest temperature in Wellington on July 20? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

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 PolyGram. 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.

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.