Highest temperature in Buenos Aires on July 18?

Platform comparison

Market context

On 18 July 2026, the highest temperature recorded at Buenos Aires' Minister Pistarini International Airport will fall into one of several defined ranges. A YES share in this market represents a bet that the day's peak temperature lands within a specific bracket; a NO share represents the opposite. Traders purchase shares at fractional prices reflecting the crowd's collective estimate of likelihood. The settlement source is historical weather data from Weather Underground, which archives daily temperature records for the airport station.

Buenos Aires experiences mid-winter conditions in July, with average highs around 13–15°C and lows near 7–9°C. Historical July records at Pistarini show considerable year-to-year variability: the coldest July highs have dipped below 5°C during cold fronts, whilst unusually warm winter days have occasionally reached 20°C or higher. The 0% crowd probability currently assigned suggests traders expect the market's highest-temperature bracket to be set at a threshold well above typical winter norms—possibly reflecting either an extreme heat event scenario or a technical setup where the defined ranges leave no realistic settlement option.

Traders should monitor Southern Hemisphere winter weather patterns in the weeks preceding mid-July 2026, particularly the position and strength of the polar vortex and any warm-air advection from the north. Argentina's meteorological service (Servicio Meteorológico Nacional) publishes extended forecasts and historical anomaly data. The settlement window closes at 12:00 UTC on 18 July, after which Weather Underground's recorded high for that calendar day becomes final.

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

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.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

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.