Highest temperature in Helsinki on July 13?

Platform comparison

Market context

Helsinki's weather on 13 July 2026 will determine which temperature bracket captures the day's peak reading at Vantaa Airport, the official measurement station. The market currently prices all temperature ranges at zero probability on Polygon, suggesting either extreme uncertainty amongst traders or insufficient liquidity to establish meaningful positions in USDC-denominated conditional tokens. Settlement hinges on Wunderground's historical data feed for that specific date, making the resolution mechanism straightforward once the day passes.

July temperatures in Helsinki historically cluster between 18–23°C, with occasional peaks reaching 25–27°C during warm spells. The city's maritime location moderates extremes; readings above 28°C occur roughly once per decade in mid-summer. The 0% crowd probability likely reflects the market's early stage rather than any expectation of anomalous conditions. Comparable July days from 2015–2024 show most highs falling in the 20–24°C range, providing a baseline for assessing which brackets hold genuine risk.

Traders monitoring this contract should track European weather forecasting updates from mid-June onwards, particularly models from the Finnish Meteorological Institute and ECMWF, which typically gain accuracy within two weeks of the target date. Any Atlantic pressure system or Scandinavian heat dome developing in early July could shift probability mass towards higher temperature brackets. The settlement window closes at 12:00 UTC on 13 July, giving traders roughly 12 hours after midnight to adjust positions based on morning forecasts before Wunderground's final reading becomes available.

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 PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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

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.