Highest temperature in Los Angeles on August 9?

Platform comparison

Market context

Los Angeles International Airport’s 9 August maximum is the key real-world input for this contract, and the market has already effectively priced in a tight outcome around the low 80s rather than a broad uncertainty band. Polymarket shows the 80–81°F bin at about 99.4%, while the contract’s own settlement rule points to Weather Underground’s Daily Observations table as the decisive source, not any headline “Day High & Low” display.[3] That means the relevant comparison is not whether Los Angeles was warm, but whether the official station maximum lands in the exact bin used for resolution.[3]

Historically, this is the sort of weather market where crowd pricing can become almost one-way once same-day observations confirm the temperature profile. Weather Underground history pages and National Weather Service time-series data for KLAX show readings already clustered around the high 70s to low 80s on 9 August, with the airport topping out in the 80–81°F range by late afternoon in the latest available observation stream.[6][9] That lines up with the dominant market price and leaves little room for a meaningful sportsbook-style disagreement; the current gap is mainly between a near-certain prediction-market consensus and the fact that any small revision in the station record still matters for settlement.[3][6]

The main catalysts are procedural rather than meteorological: the final Daily Observations entries, any late data corrections, and the timestamp at which Weather Underground posts the first observation for the following day, because the market explicitly allows revisions only until then.[3] National Weather Service forecast products for the Los Angeles area were still active over the settlement window, but by this stage the trade is mostly about data publication, not forecast uncertainty.[12][13] In comparison terms, analyst consensus appears close to the exchange price, and there is no visible sportsbook line in the supplied sources that materially challenges the 99% crowd view; the practical watchpoint is whether the published KLAX maximum is confirmed cleanly in the historical record.[3][9]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

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.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Best Prediction Markets trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.