Highest temperature in Los Angeles on August 9?

Platform comparison

Market context

Polymarket is pricing the Los Angeles temperature contract as a near-certain **80-81°F** outcome, with the market at 99.4% YES on that band and the rest of the ladder effectively stranded. Because settlement is in USDC on Polygon through conditional tokens, the relevant question for traders is not whether Los Angeles was generally warm, but whether the **highest** KLAX reading captured in Weather Underground’s Daily Observations table lands inside the specified bin before the market’s cutoff and final data lock.

That 99%+ pricing is consistent with how similar late-summer Los Angeles temperature markets have resolved when the airport max came in close to seasonal norms rather than extreme heat. The National Weather Service’s climate products put Los Angeles around the mid-80s on an average August 9, while a recent KTLA report on August heat noted KLAX setting a new daily record of 82°F in one event, underscoring how coastal airport highs often sit in a narrow range rather than swinging dramatically. Time-and-date’s historic weather page also shows Los Angeles topping out in the low 80s on comparable summer days, which helps explain why the current contract is not behaving like a binary heatwave bet.

For traders, the main catalyst is not a forecast revision but the final observation sequence on Weather Underground’s KLAX page, because the market resolves only after the first datapoint for the following date appears and any later edits are ignored. The practical dependency is the station feed itself: if late-day warmth pushes the Daily Observations table up or down by a degree, the contract can flip between adjacent bins, even though the broader forecast from the National Weather Service stayed centred near the upper 70s to low 80s.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Los Angeles on August 9? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.