Highest temperature in NYC on August 3?

Platform comparison

Market context

LaGuardia’s **highest temperature** on 3 August will be set by the warmest reading in the airport station’s Wunderground daily history, so the market is really about a single-location peak rather than New York City as a whole. With the crowd currently pricing **0% YES**, the implied view is that the eventual reading will fall outside the contract’s required range, although on Polymarket those prices are shown as implied probabilities, while on Kalshi and Betfair the same event would typically be read through contract price or decimal-odds conventions rather than a straight percentage.

Historical context suggests the relevant zone is usually the low-to-mid 80s Fahrenheit for a hot New York August day, which makes the present crowd stance unusually bearish relative to normal summer heat. Polymarket’s comparable event page had the leading bins clustered around **82–85°F** before settlement, with the top two outcomes separated by only a couple of points, showing how sensitive these markets are to small shifts in forecast guidance and how thin the edge can be between adjacent temperature bands.[1] For comparison, weather-history sources for New York in August commonly show daily maxima in the low 80s, reinforcing that a zero-per-cent price is not the same thing as a zero-per-cent physical chance.[4][5]

Traders should watch any late forecast changes, thunderstorm timing, and whether the city’s afternoon heating is cut short by cloud cover or rainfall, because airport observations can diverge from broader city forecasts. CBS News reported a flash-flooding threat for the NYC area on 3 August, which matters because convection and storm outflows can cap the day’s maximum temperature if they arrive before the afternoon peak.[7] On platform mechanics, this sort of market can also price differently because fees and access are not uniform: Polymarket uses crypto-based trading and shows implied probabilities directly, while Kalshi and Betfair-style books may involve different fee schedules, account checks, and jurisdictional KYC reach, which can leave the same weather view expressed at different headline prices.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in NYC on August 3? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Robinhood Prediction Markets, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). On-chain settlement clears in minutes — the fastest payout path of the four.

FAQ

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Robinhood Prediction Markets has a different geo footprint and routes to Polymarket's order book at 0% fees.

Are all these platforms regulated?

No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.