Official Automated Surface Observing System (ASOS) measurements at San Francisco International Airport (KSFO), the market's resolution source via Weather Underground, recorded a daily high temperature of 64-65°F on May 13, 2026, driving trader consensus to a 99.2% implied probability for this outcome. Persistent marine stratus clouds and strong westerly winds from the Pacific suppressed daytime heating, aligning with typical mid-May climatology where coastal fog often caps highs below 70°F despite sunnier inland conditions. National Weather Service preliminary data supports this, with final daily climate summary pending in 24-48 hours. Realistic challenges would require a rare data revision from a late-afternoon peak or sensor anomaly, though historical precedents show such adjustments affect less than 1% of observations.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedHighest temperature in San Francisco on May 13?
Highest temperature in San Francisco on May 13?
$50,253 Vol.
$50,253 Vol.
64-65°F
99%
66°F or higher
1%
$50,253 Vol.
$50,253 Vol.
64-65°F
99%
66°F or higher
1%
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the San Francisco International Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/us/ca/san-francisco/KSFO.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve to "Yes" until all data for this date has been finalized.
The resolution source for this market measures temperatures to whole degrees Fahrenheit (eg, 21°F). Thus, this is the level of precision that will be used when resolving the market.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.
Market Opened: May 11, 2026, 12:11 AM ET
Resolution Source
https://www.wunderground.com/history/daily/us/ca/san-francisco/KSFOResolver
0x69c47De9D...The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the San Francisco International Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/us/ca/san-francisco/KSFO.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve to "Yes" until all data for this date has been finalized.
The resolution source for this market measures temperatures to whole degrees Fahrenheit (eg, 21°F). Thus, this is the level of precision that will be used when resolving the market.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.
Resolution Source
https://www.wunderground.com/history/daily/us/ca/san-francisco/KSFOResolver
0x69c47De9D...Official Automated Surface Observing System (ASOS) measurements at San Francisco International Airport (KSFO), the market's resolution source via Weather Underground, recorded a daily high temperature of 64-65°F on May 13, 2026, driving trader consensus to a 99.2% implied probability for this outcome. Persistent marine stratus clouds and strong westerly winds from the Pacific suppressed daytime heating, aligning with typical mid-May climatology where coastal fog often caps highs below 70°F despite sunnier inland conditions. National Weather Service preliminary data supports this, with final daily climate summary pending in 24-48 hours. Realistic challenges would require a rare data revision from a late-afternoon peak or sensor anomaly, though historical precedents show such adjustments affect less than 1% of observations.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated



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