Highest temperature in Helsinki on July 4?

Platform comparison

Market context

The real-world event driving this market is the highest temperature recorded at Helsinki Vantaa Airport on 4 July 2026, measured in degrees Celsius. In prediction markets, a YES share pays out if the outcome falls within the specified temperature range, while a NO share pays out if it does not. The current crowd-implied probability of 0% for YES suggests traders believe the temperature will not hit the target range, likely because early July in Helsinki typically starts cool before warming later in the month.

Historical patterns show that July in Helsinki begins with cooler days, such as 2 July 2026, which dropped to 13.4°C, before rising to a peak of 22.6°C on 28 July 2026 [2]. A record-breaking heatwave with temperatures above 30°C ended July 2026 in some parts of Finland, but this occurred late in the month, not early [1]. Traders should watch for meteorological announcements regarding early-month heatwaves, as these are rare but possible catalysts. Recent forecasts indicate daily highs in Helsinki Vantaa Airport for July 2026 will range from 65°F to 74°F (approximately 18°C to 23°C), with overnight lows between 46°F and 58°F [5]. No major weather events have been announced for early July yet, so the 0% probability aligns with the typical cool start to the month.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Prediction Market UK, which mirrors the Polymarket order book directly.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.