Highest temperature in NYC on August 9?

Platform comparison

Market context

The real-world event is the **maximum temperature at LaGuardia Airport on 9 August 2026**, with the market settling off Weather Underground’s *Daily Observations* table rather than the summary high/low box. That detail matters because platforms can display the same day differently: Polymarket’s contract page currently shows a 73% crowd-implied chance for the 90-91°F band, while the underlying market is still framed around a single station reading at KLGA.[1]

For historical context, late-summer New York highs in the low 90s are common enough that the current 0% yes price looks like an outlier only if the market is being read as a plain-weather call rather than a resolution-specific one. WeatherSpark’s live Manhattan page for 9 August showed KLGA near 88°F with a 6-hour high of 89.1°F during the day, which sits close to the 90-91°F bucket that Polymarket was leading on.[2] On comparative books, Polymarket tends to quote as direct probabilities, whereas Kalshi and Betfair-style markets are typically easier to read in price or decimal terms, and fees/KYC rules differ materially: Betfair’s exchange model usually adds commission, while some rivals restrict access by jurisdiction more tightly than crypto-native venues. Those structural differences matter more in a narrow weather contract than in a broad macro event, because a one-degree read can move the settlement band.

The main catalysts are the afternoon temperature trace at LaGuardia and any late-day shifts in cloud cover, sea breeze, or convection that can cap the high before the settlement window closes at 12:00 UTC. Traders should also watch the National Weather Service New York forecast and briefing products for same-day adjustments, since airport observations can diverge from city-centre expectations even when forecasts are stable.[3][9][13]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in NYC on August 9? 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 Polymarket Alternative, 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

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

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.

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.

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.