Highest temperature in Buenos Aires on May 22?

Platform comparison

Active sub-markets

Market context

Buenos Aires airport temperatures in late May are usually mild rather than hot, so the market sits on whether 22 May produces an unusually warm afternoon before the day closes at 12:00 UTC. Long-run May averages for Buenos Aires point to highs around 19°C, with typical daily maxima more often in the high teens than above 20°C. That makes the top temperature bands materially more plausible than an extreme-heat outcome. A 0% crowd-implied chance on the highest bands is therefore more a reflection of the city’s autumn climate than a statement that the reading cannot briefly spike if conditions turn sunny and dry.

For comparison, Polymarket generally shows the market as a direct yes/no probability, while Kalshi and Betfair usually price the same kind of event through odds or contract prices that need converting back into implied probabilities; Smarkets also quotes a market price but with different fee treatment and liquidity conditions. That matters here because a small move in expectation around the noon UTC cutoff can look very different across books. KYC access is another practical divider: Kalshi’s reach and account checks differ from Polymarket’s crypto-based access model, while Betfair and Smarkets are more conventional exchange venues with broader fiat onboarding but stricter jurisdictional constraints.

The key traders’ watchpoints are the local morning forecast for Ezeiza, cloud cover, wind direction, and whether any frontal system moves through before the settlement window closes. Because the market resolves on the highest temperature recorded by the Minister Pistarini Intl Airport Station during the full day, a brief late-morning or early-afternoon warm-up matters more than the evening trend. If forecasts on Weather Underground and mainstream services converge on low-20s Celsius by midday local time, the higher bands become live; if not, the result is likely to sit in the cooler ranges.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Buenos Aires on May 22? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live quote comes directly from the Polygon order book; the other three are listed with their platform attributes — fees, KYC, settlement currency, payment options — because a 1:1 contract comparison without API access would be guesswork.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

Where can I trade this market with the lowest fees?

On PolyGram, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

PolyGram is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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 it cost to trade on PolyGram?

Zero. PolyGram routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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.