Highest temperature in NYC on August 9?

Platform comparison

Market context

August 9 in New York City finished as a **warm-to-hot summer day**, with LaGuardia already reporting 88.0°F in the early afternoon and a 6-hour high of 89.1°F in the Weather Underground-style observation feed, which places the market squarely in the upper-80s to low-90s band rather than at the far tail of the distribution.[1] For this contract, the key point is that settlement turns on the **highest reading in Daily Observations** at LaGuardia, not the headline “Day High & Low” summary, so traders are really pricing the station’s intraday peak, not a citywide average or forecast figure.[4]

The current **0% YES** crowd price is notable because comparable late-summer NYC highs often cluster tightly: AccuWeather’s August outlook has August 9 near 90°F, while nearby days are only a degree or two apart, suggesting that a single-degree bin can easily decide these markets.[2] Polymarket shows the same event trading with outcome buckets in **implied probability** terms, whereas Kalshi-style yes/no contracts are generally quoted as contract prices, and Betfair or Smarkets would instead show **decimal odds** with exchange commission layered on top; that means the apparent “cheapness” or “expensiveness” of the market is not directly comparable across platforms.[4]

The main catalysts are mundane but decisive: the final daily observation sequence at LaGuardia, any late-day warm surge before the first datapoint for 10 August is published, and any subsequent revision to the station record before the market’s cut-off.[4] Weather.gov’s New York forecast page and local climate products are useful for context, but they do not override the contract’s specified Weather Underground source, so traders should watch the actual station feed rather than broader borough forecasts.[3][12][13] Access also differs by venue: Polymarket-style crypto rails are broader in reach, while Kalshi, Betfair and Smarkets impose different KYC and geographic restrictions, which can affect liquidity and the speed at which the market reprices.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in NYC on August 9? 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

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.

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.

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. Kalshi Alternative has a different geo footprint and routes to Polymarket's order book at 0% fees.