Highest temperature in NYC on August 7?

Platform comparison

Market context

The key question is whether LaGuardia Airport peaked anywhere in the *high 80s, low 90s, or above* on 7 August, because this market settles on the highest reading in Weather Underground’s Daily Observations table rather than the broader “Day High & Low” summary. Weather Underground’s history page for New York City already shows an 82°F report from John F. Kennedy Intl Airport Station for the date, while the market contract is explicitly tied to LaGuardia Airport Station, so the exact station and the final daily observation matter more than headline city-wide weather summaries.[5][7]

For comparison, Polymarket’s live event page currently prices the outcome distribution around **90–91°F** as the leading bracket, with **88–89°F** next, implying the crowd is expecting a warm but not exceptional Manhattan-area high rather than a record-setting spike.[3] On more mature books such as Kalshi, the same kind of question is usually quoted in decimal-style contract prices, while Betfair and Smarkets present exchange odds and charges differently; that means the same temperature band can look cheaper or pricier depending on whether you are reading implied probability, raw decimal pricing, or exchange commission. Historical New York summer highs also show that mid-to-upper 80s is a routine outcome, while 90°F-plus is plausible but less frequent, so a 0% YES crowd view would generally be read as an extreme misprice only if the station log later prints a clearly higher peak.[4]

The main catalysts are the hourly observation trail and any late revisions in Weather Underground’s daily table, because the contract allows revisions only until the first datapoint for the following date is published.[3] Traders should watch the LaGuardia station’s overnight and early-morning final entries, plus any convective showers or sea-breeze effects that can cap the afternoon maximum in New York; the National Weather Service’s local forecast page and climate products are useful cross-checks for whether the day was forecast to run hot enough to break into the top bracket.[8][11] Kratky gaps between platforms matter here: Polymarket’s crowd price is a simple implied probability, whereas Kalshi-style markets and exchange books can move on fee-adjusted liquidity and may be constrained by jurisdictional KYC, so the same weather outcome can trade with different apparent confidence across venues.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in NYC on August 7? 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 Kalshi Alternative, which mirrors the Polymarket order book at 0% fees.

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

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.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Kalshi Alternative offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.