A cutoff low moving into California is the main driver behind trader consensus favoring 64–67°F highs in San Francisco on September 20, with the 66–67°F bin holding the highest implied probability at 41%. National Weather Service forecasts show a deepened marine layer and increased onshore flow under mostly cloudy conditions, suppressing temperatures 5–10°F below recent readings and seasonal normals near 71°F. Model guidance aligns on this range while noting microclimate variability and exact stratus timing as key uncertainties. Official resolution will depend on the NWS maximum at downtown San Francisco, with any shift in the low’s position or wind patterns able to alter the final value before tomorrow’s close.
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 September 20?
Highest temperature in San Francisco on September 20?
66-67°F 41%
64-65°F 32%
68-69°F 19%
70-71°F 6%
NEW
NEW
Sep 20, 2026
59°F or below
1%
60-61°F
2%
62-63°F
5%
64-65°F
32%
66-67°F
41%
68-69°F
19%
70-71°F
6%
72-73°F
3%
74-75°F
1%
76-77°F
1%
78°F or higher
<1%
66-67°F 41%
64-65°F 32%
68-69°F 19%
70-71°F 6%
NEW
NEW
Sep 20, 2026
59°F or below
$174 Vol.
1%
60-61°F
$10 Vol.
2%
62-63°F
$266 Vol.
5%
64-65°F
$1,342 Vol.
32%
66-67°F
$382 Vol.
41%
68-69°F
$842 Vol.
19%
70-71°F
$412 Vol.
6%
72-73°F
$568 Vol.
3%
74-75°F
$135 Vol.
1%
76-77°F
$15 Vol.
1%
78°F or higher
$111 Vol.
<1%
This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the San Francisco International Airport Station in degrees Fahrenheit on 20 Sep '26.
The resolution source for this market will be information from NOAA, specifically the highest reading under the "Temp" column for all times on this day, available here: https://www.weather.gov/wrh/timeseries?site=ksfo
This market will resolve off of the Hourly Data provided using the "Show Hourly Data" button.
If NOAA data for the observation date is unavailable by 11:59 PM ET on the day following the observation date, the Weather Underground Daily Observations table will be used as the resolution source.
In the event that there is no data for the observation date by 11:59 PM ET on the day following the observation date, this market will resolve to the lowest bracket.
To toggle between Fahrenheit and Celsius, click the "Switch to US Units w/ kts" button until the relevant table displays °F.
This market will resolve once the first data point for the following date has been published on the resolution source, or by 11:59 PM ET on the day following the observation date, whichever comes first.
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.
Revisions to temperatures recorded within this market's timeframe will be considered until the first datapoint for the following date has been published, after which any alterations will not be considered.A cutoff low moving into California is the main driver behind trader consensus favoring 64–67°F highs in San Francisco on September 20, with the 66–67°F bin holding the highest implied probability at 41%. National Weather Service forecasts show a deepened marine layer and increased onshore flow under mostly cloudy conditions, suppressing temperatures 5–10°F below recent readings and seasonal normals near 71°F. Model guidance aligns on this range while noting microclimate variability and exact stratus timing as key uncertainties. Official resolution will depend on the NWS maximum at downtown San Francisco, with any shift in the low’s position or wind patterns able to alter the final value before tomorrow’s close.
This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the San Francisco International Airport Station in degrees Fahrenheit on 20 Sep '26.
The resolution source for this market will be information from NOAA, specifically the highest reading under the "Temp" column for all times on this day, available here: https://www.weather.gov/wrh/timeseries?site=ksfo
This market will resolve off of the Hourly Data provided using the "Show Hourly Data" button.
If NOAA data for the observation date is unavailable by 11:59 PM ET on the day following the observation date, the Weather Underground Daily Observations table will be used as the resolution source.
In the event that there is no data for the observation date by 11:59 PM ET on the day following the observation date, this market will resolve to the lowest bracket.
To toggle between Fahrenheit and Celsius, click the "Switch to US Units w/ kts" button until the relevant table displays °F.
This market will resolve once the first data point for the following date has been published on the resolution source, or by 11:59 PM ET on the day following the observation date, whichever comes first.
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.
Revisions to temperatures recorded within this market's timeframe will be considered until the first datapoint for the following date has been published, after which any alterations will not be considered.
The resolution source for this market will be information from NOAA, specifically the highest reading under the "Temp" column for all times on this day, available here: https://www.weather.gov/wrh/timeseries?site=ksfo
This market will resolve off of the Hourly Data provided using the "Show Hourly Data" button.
If NOAA data for the observation date is unavailable by 11:59 PM ET on the day following the observation date, the Weather Underground Daily Observations table will be used as the resolution source.
In the event that there is no data for the observation date by 11:59 PM ET on the day following the observation date, this market will resolve to the lowest bracket.
To toggle between Fahrenheit and Celsius, click the "Switch to US Units w/ kts" button until the relevant table displays °F.
This market will resolve once the first data point for the following date has been published on the resolution source, or by 11:59 PM ET on the day following the observation date, whichever comes first.
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.
Revisions to temperatures recorded within this market's timeframe will be considered until the first datapoint for the following date has been published, after which any alterations will not be considered.
Market Opened: Sep 18, 2026, 7:56 AM ET
Volume
$4,256End Date
Sep 20, 2026Market Opened
Sep 18, 2026, 7:56 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=ksfoResolver
0x69c47De9D...This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the San Francisco International Airport Station in degrees Fahrenheit on 20 Sep '26.
The resolution source for this market will be information from NOAA, specifically the highest reading under the "Temp" column for all times on this day, available here: https://www.weather.gov/wrh/timeseries?site=ksfo
This market will resolve off of the Hourly Data provided using the "Show Hourly Data" button.
If NOAA data for the observation date is unavailable by 11:59 PM ET on the day following the observation date, the Weather Underground Daily Observations table will be used as the resolution source.
In the event that there is no data for the observation date by 11:59 PM ET on the day following the observation date, this market will resolve to the lowest bracket.
To toggle between Fahrenheit and Celsius, click the "Switch to US Units w/ kts" button until the relevant table displays °F.
This market will resolve once the first data point for the following date has been published on the resolution source, or by 11:59 PM ET on the day following the observation date, whichever comes first.
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.
Revisions to temperatures recorded within this market's timeframe will be considered until the first datapoint for the following date has been published, after which any alterations will not be considered.A cutoff low moving into California is the main driver behind trader consensus favoring 64–67°F highs in San Francisco on September 20, with the 66–67°F bin holding the highest implied probability at 41%. National Weather Service forecasts show a deepened marine layer and increased onshore flow under mostly cloudy conditions, suppressing temperatures 5–10°F below recent readings and seasonal normals near 71°F. Model guidance aligns on this range while noting microclimate variability and exact stratus timing as key uncertainties. Official resolution will depend on the NWS maximum at downtown San Francisco, with any shift in the low’s position or wind patterns able to alter the final value before tomorrow’s close.
This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the San Francisco International Airport Station in degrees Fahrenheit on 20 Sep '26.
The resolution source for this market will be information from NOAA, specifically the highest reading under the "Temp" column for all times on this day, available here: https://www.weather.gov/wrh/timeseries?site=ksfo
This market will resolve off of the Hourly Data provided using the "Show Hourly Data" button.
If NOAA data for the observation date is unavailable by 11:59 PM ET on the day following the observation date, the Weather Underground Daily Observations table will be used as the resolution source.
In the event that there is no data for the observation date by 11:59 PM ET on the day following the observation date, this market will resolve to the lowest bracket.
To toggle between Fahrenheit and Celsius, click the "Switch to US Units w/ kts" button until the relevant table displays °F.
This market will resolve once the first data point for the following date has been published on the resolution source, or by 11:59 PM ET on the day following the observation date, whichever comes first.
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.
Revisions to temperatures recorded within this market's timeframe will be considered until the first datapoint for the following date has been published, after which any alterations will not be considered.
The resolution source for this market will be information from NOAA, specifically the highest reading under the "Temp" column for all times on this day, available here: https://www.weather.gov/wrh/timeseries?site=ksfo
This market will resolve off of the Hourly Data provided using the "Show Hourly Data" button.
If NOAA data for the observation date is unavailable by 11:59 PM ET on the day following the observation date, the Weather Underground Daily Observations table will be used as the resolution source.
In the event that there is no data for the observation date by 11:59 PM ET on the day following the observation date, this market will resolve to the lowest bracket.
To toggle between Fahrenheit and Celsius, click the "Switch to US Units w/ kts" button until the relevant table displays °F.
This market will resolve once the first data point for the following date has been published on the resolution source, or by 11:59 PM ET on the day following the observation date, whichever comes first.
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.
Revisions to temperatures recorded within this market's timeframe will be considered until the first datapoint for the following date has been published, after which any alterations will not be considered.
Volume
$4,256End Date
Sep 20, 2026Market Opened
Sep 18, 2026, 7:56 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=ksfoResolver
0x69c47De9D...A cutoff low moving into California is the main driver behind trader consensus favoring 64–67°F highs in San Francisco on September 20, with the 66–67°F bin holding the highest implied probability at 41%. National Weather Service forecasts show a deepened marine layer and increased onshore flow under mostly cloudy conditions, suppressing temperatures 5–10°F below recent readings and seasonal normals near 71°F. Model guidance aligns on this range while noting microclimate variability and exact stratus timing as key uncertainties. Official resolution will depend on the NWS maximum at downtown San Francisco, with any shift in the low’s position or wind patterns able to alter the final value before tomorrow’s close.
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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