Highest temperature in Los Angeles on August 17?

Platform comparison

Market context

Los Angeles’s highest temperature on 17 August is likely to sit in the upper 80s Fahrenheit, with live forecast products pointing to a warm but not extreme day and Weather Underground already showing 89°F by late morning at LAX.[1][2][13] That leaves the contract in a range where a midday or afternoon high a degree or two either side of 90°F matters, but the crowd-implied probability of 0% YES looks detached from the available weather signals rather than a clean market read.

Comparable warm-season cases in Southern California usually settle around the forecast high band rather than the single headline figure, which is why traders focus on station-specific observations and not citywide summaries. AccuWeather’s August outlook has Los Angeles running 80°F to 91°F on daily highs, while the National Weather Service discussion flagged continued warming and temperatures above normal across much of the region.[2][4] On that framing, consensus points to a high-80s result, with only a modest chance of a low-90s print if cloud cover breaks early and inland heat bleeds west.

The key catalyst is the day’s realised marine-layer evolution at Los Angeles International Airport, because the market settles from Weather Underground’s Daily Observations table for that station, not the Day High & Low summary.[9] Traders should watch the mid-morning to mid-afternoon observation sequence, since the highest reading often comes before sea-breeze reinforcement or coastal cloud return caps the temperature; the broader Southern California heat pattern also remains supportive of warmer-than-normal afternoons.[4][11]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Los Angeles on August 17? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Kalshi vs Polymarket, which mirrors the Polymarket order book at 0% fees.

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

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 Kalshi vs Polymarket. 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.