Current National Weather Service forecasts and ensemble model runs show San Francisco reaching a daily high of at least 68°F on May 18, with a building high-pressure ridge suppressing the typical marine layer and permitting warmer continental air to advect toward the coast. This synoptic setup aligns with historical May patterns when offshore flow produces above-average temperatures, and recent model consensus leaves little room for significant cooling. Trader consensus has priced the 68°F-or-higher outcome near 99 percent because only a rapid marine-layer resurgence or unforecasted cold-air advection could keep readings below that threshold. Updated guidance later today or tomorrow morning will provide the final observational check before resolution.
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 18?
Highest temperature in San Francisco on May 18?
68°F or higher 99.0%
66-67°F <1%
49°F or below <1%
60-61°F <1%
NEW
NEW
May 18, 2026
49°F or below
<1%
50-51°F
<1%
52-53°F
<1%
54-55°F
<1%
56-57°F
<1%
58-59°F
<1%
60-61°F
<1%
62-63°F
<1%
64-65°F
<1%
66-67°F
1%
68°F or higher
99%
68°F or higher 99.0%
66-67°F <1%
49°F or below <1%
60-61°F <1%
NEW
NEW
May 18, 2026
49°F or below
$473 Vol.
<1%
50-51°F
$265 Vol.
<1%
52-53°F
$395 Vol.
<1%
54-55°F
$395 Vol.
<1%
56-57°F
$557 Vol.
<1%
58-59°F
$720 Vol.
<1%
60-61°F
$1,520 Vol.
<1%
62-63°F
$2,037 Vol.
<1%
64-65°F
$1,384 Vol.
<1%
66-67°F
$921 Vol.
1%
68°F or higher
$1,240 Vol.
99%
This market will resolve to the temperature range that contains the highest temperature recorded at the San Francisco International Airport Station in degrees Fahrenheit on 18 May '26.
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.Current National Weather Service forecasts and ensemble model runs show San Francisco reaching a daily high of at least 68°F on May 18, with a building high-pressure ridge suppressing the typical marine layer and permitting warmer continental air to advect toward the coast. This synoptic setup aligns with historical May patterns when offshore flow produces above-average temperatures, and recent model consensus leaves little room for significant cooling. Trader consensus has priced the 68°F-or-higher outcome near 99 percent because only a rapid marine-layer resurgence or unforecasted cold-air advection could keep readings below that threshold. Updated guidance later today or tomorrow morning will provide the final observational check before resolution.
This market will resolve to the temperature range that contains the highest temperature recorded at the San Francisco International Airport Station in degrees Fahrenheit on 18 May '26.
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.
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 16, 2026, 12:05 AM ET
Volume
$9,901End Date
May 18, 2026Market Opened
May 16, 2026, 12:05 AM ETResolution Source
https://www.wunderground.com/history/daily/us/ca/san-francisco/KSFOThis market will resolve to the temperature range that contains the highest temperature recorded at the San Francisco International Airport Station in degrees Fahrenheit on 18 May '26.
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.Current National Weather Service forecasts and ensemble model runs show San Francisco reaching a daily high of at least 68°F on May 18, with a building high-pressure ridge suppressing the typical marine layer and permitting warmer continental air to advect toward the coast. This synoptic setup aligns with historical May patterns when offshore flow produces above-average temperatures, and recent model consensus leaves little room for significant cooling. Trader consensus has priced the 68°F-or-higher outcome near 99 percent because only a rapid marine-layer resurgence or unforecasted cold-air advection could keep readings below that threshold. Updated guidance later today or tomorrow morning will provide the final observational check before resolution.
This market will resolve to the temperature range that contains the highest temperature recorded at the San Francisco International Airport Station in degrees Fahrenheit on 18 May '26.
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.
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.
Volume
$9,901End Date
May 18, 2026Market Opened
May 16, 2026, 12:05 AM ETResolution Source
https://www.wunderground.com/history/daily/us/ca/san-francisco/KSFOCurrent National Weather Service forecasts and ensemble model runs show San Francisco reaching a daily high of at least 68°F on May 18, with a building high-pressure ridge suppressing the typical marine layer and permitting warmer continental air to advect toward the coast. This synoptic setup aligns with historical May patterns when offshore flow produces above-average temperatures, and recent model consensus leaves little room for significant cooling. Trader consensus has priced the 68°F-or-higher outcome near 99 percent because only a rapid marine-layer resurgence or unforecasted cold-air advection could keep readings below that threshold. Updated guidance later today or tomorrow morning will provide the final observational check before resolution.
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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