Highest temperature in NYC on August 3?

Platform comparison

Market context

On 3 August, the relevant real-world event is the **highest temperature recorded at LaGuardia Airport in New York City**, with the market resolving to the range that contains that day’s peak reading. On Polymarket, the current book is effectively pricing a split between **82–83°F** and **84–85°F**, both in the low-to-mid 30s, while the “0% YES” implied probability in a different venue setup should be read cautiously because this market is range-based rather than a simple yes/no question.[1]

Historically, late-summer New York City highs often cluster in the low-to-mid 80s, which makes narrow adjacent bins the key comparison for traders rather than a single exact print. That is visible in the current Polymarket ladder, where the market has concentrated around 82–85°F, and in weather-history style datasets that show New York’s August daily maxima commonly sitting near that band.[1][5] For a platform comparison, the same temperature event can look different across books: Polymarket typically shows **implied probability** for each range, whereas Kalshi-style contracts are quoted in **decimal price terms**; Betfair and Smarkets may display back/lay prices and net the trading cost differently, so the same view can translate into different headline odds after fees and spread. KYC access also varies materially by venue, with US-regulated prediction markets generally applying tighter customer checks than offshore exchange-style books.

The main catalysts are the official readings themselves: any late revisions to the LaGuardia history page can still matter until the next day’s first datapoint is published, because this market uses the final daily maximum from Wunderground’s history feed.[1] For traders, the practical watchpoints are the intra-day weather evolution, any convective showers or thunderstorm timing that cap the afternoon high, and whether nearby official forecasts or National Weather Service guidance drift a degree or two higher or lower before the market settles.[1][10][14] A faster afternoon cooling trend favours the lower 82–83°F band; sustained sun and delayed storm activity would support 84–85°F or above.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in NYC on August 3? 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 mid is the canonical probability; the side-by-side columns benchmark fees, KYC, settlement currency and deposit rails so you can choose the venue that fits your jurisdiction and trade size.

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.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

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.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Kalshi Alternative 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.