Highest temperature in Wellington on August 5?

Platform comparison

Market context

Wellington’s airport station is typically a cool, windy late-winter location, so the market is really about whether the day’s *highest* reading can push beyond the low-teens Celsius band that usually frames August there. Historical and forecast-style references for Wellington in August cluster around highs of roughly 9°C to 12°C, with occasional 13°C readings, which helps explain why the crowd has marked a 0% YES probability for a threshold requiring a notably warmer outcome.[3][6][8][10]

For a same-day weather contract like this, the key catalyst is the actual airport observation path rather than the broader city forecast: a brief northerly, clearer-than-expected interval, or a localised warmer burst around midday can lift the day’s maximum, while rain bands and stronger southerlies usually cap the ceiling. Recent live reporting already showed Wellington/Intl around 10°C with high humidity and a northerly breeze, consistent with the sort of conditions that keep afternoon highs subdued unless the air mass changes materially.[2][9][13]

From a market-structure angle, settlement is in USDC but the underlying risk is still a binary weather print, so the main trade is whether the day’s max lands in the next temperature bracket or misses it entirely. In crypto terms, BTC/ETH spot direction and funding rates matter mainly for collateral conditions and broad risk appetite, not for the weather outcome itself; the contract should trade on local meteorology and station-level observation updates rather than on-chain flows unless those flows are moving the market’s capacity to hold risk.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — sit alongside as off-chain reference points so you can see how the contract translates across regulatory and settlement regimes.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

FAQ

Why USDC and not ETH or USDT?

USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.

What does a transaction cost on Polygon?

Polygon gas is typically under $0.01 per transaction. A full trade cycle (Approve + Order + Fill) totals around $0.03 — compared to $5-50 on Ethereum mainnet.

Can I use Bitcoin directly?

No, Polymarket operates exclusively in USDC on Polygon. You can bridge BTC to USDC via an exchange or bridge service and deposit on Polygon — typically 10-30 minutes processing time.

How does UMA secure the resolution?

The UMA Optimistic Oracle uses a bond system: a proposer posts a bond, a two-hour challenge window opens. On dispute the losing side forfeits the bond — financial incentive for honest resolution.

How volatile are crypto prediction markets?

Crypto markets react to spot prices — a 5% BTC move typically shifts a "BTC above X by date" market 10-20%. Polymarket crypto market liquidity is usually six-figure USD, sufficient for active trading.