Highest temperature in San Francisco on August 10?

Platform comparison

Market context

San Francisco’s highest temperature is likely to be set by the usual late-summer marine layer pattern at San Francisco International Airport, where morning cloud and afternoon clearing often keep daily maxima close to the upper 60s or low 70s Fahrenheit. For this market, the key detail is that resolution depends on the **Daily Observations** table on Weather Underground, so a programmatic workflow should query the station history directly rather than rely on any summary high/low widget. Weather Underground’s San Francisco history page and station-observation records are the relevant sources for the eventual settlement value.[2][8][12]

The current 0% crowd-implied probability on YES is best read as a signalling artefact rather than a literal forecast, because the market is already past its settlement window and the outcome should now be observable from the recorded station data. Comparable August data point to a narrow spread: the climatological normal maximum at San Francisco Airport for 10 August is 73°F, while the record maximum for that date is 87°F, and recent historical pages show daily highs clustering around the high 60s to low 70s.[6][7][12] For a trader building tooling, that means the practical check is to pull the highest hourly or sub-hourly observation for KSFO on 10 August 2026 and map it to the market’s temperature band.

The main catalysts are the cadence of station updates and any late-day thermal bump from clearing, which can matter more than forecast headlines in coastal San Francisco. National Weather Service conditions for the area were still showing a cool, humid morning reading just after 01:43 AM PDT, underscoring that the session starts from a marine-influenced baseline rather than an inland heat set-up.[14] A power-user would therefore watch the station feed, watch for any discrepancy between Weather Underground’s summary and its Daily Observations table, and only then trigger a conditional order or automated settlement check once the final observation for the day is available.[2][8]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Kalshi Fees, which mirrors the Polymarket order book directly.

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 Fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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 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 Kalshi Fees trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.