Recent National Weather Service observations at San Francisco International Airport recorded a daily minimum of 58°F on September 21, two degrees above the 1991–2020 normal of 56°F, amid persistent marine layer influence and patchy fog that moderated overnight cooling. Trader sentiment remains tightly split between the 54–55°F and 56–57°F bins because official lows can vary by a degree or two across downtown versus airport stations, depending on exact siting, wind patterns from the Pacific high, and the precise timing of the coldest hour near dawn. Historical September averages near 55.7°F and the absence of strong onshore flow or clear-sky radiational cooling kept probabilities from shifting decisively lower, while upcoming final climatological summaries may resolve any minor discrepancies between preliminary reports and verified daily extremes.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedLowest temperature in San Francisco on September 21?
Lowest temperature in San Francisco on September 21?
56-57°F 100%
51°F or below <1%
52-53°F <1%
54-55°F <1%
$1,773 Vol.
$1,773 Vol.
Sep 21, 2026
51°F or below
No
52-53°F
No
54-55°F
No
56-57°F
Yes
58-59°F
No
60-61°F
No
62-63°F
No
64-65°F
No
66-67°F
No
68-69°F
No
70°F or higher
No
56-57°F 100%
51°F or below <1%
52-53°F <1%
54-55°F <1%
$1,773 Vol.
$1,773 Vol.
Sep 21, 2026
51°F or below
$0 Vol.
No
52-53°F
$15 Vol.
No
54-55°F
$15 Vol.
No
56-57°F
$224 Vol.
Yes
58-59°F
$1,494 Vol.
No
60-61°F
$5 Vol.
No
62-63°F
$0 Vol.
No
64-65°F
$0 Vol.
No
66-67°F
$0 Vol.
No
68-69°F
$0 Vol.
No
70°F or higher
$20 Vol.
No
This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the San Francisco International Airport Station in degrees Fahrenheit on 21 Sep '26.
The resolution source for this market will be information from NOAA, specifically the lowest 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.Recent National Weather Service observations at San Francisco International Airport recorded a daily minimum of 58°F on September 21, two degrees above the 1991–2020 normal of 56°F, amid persistent marine layer influence and patchy fog that moderated overnight cooling. Trader sentiment remains tightly split between the 54–55°F and 56–57°F bins because official lows can vary by a degree or two across downtown versus airport stations, depending on exact siting, wind patterns from the Pacific high, and the precise timing of the coldest hour near dawn. Historical September averages near 55.7°F and the absence of strong onshore flow or clear-sky radiational cooling kept probabilities from shifting decisively lower, while upcoming final climatological summaries may resolve any minor discrepancies between preliminary reports and verified daily extremes.
This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the San Francisco International Airport Station in degrees Fahrenheit on 21 Sep '26.
The resolution source for this market will be information from NOAA, specifically the lowest 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 lowest 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 19, 2026, 7:29 AM ET
Volume
$1,773End Date
Sep 21, 2026Market Opened
Sep 19, 2026, 7:29 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=ksfoResolver
0x69c47de9d...Outcome proposed: No
No dispute
Final outcome: No
This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the San Francisco International Airport Station in degrees Fahrenheit on 21 Sep '26.
The resolution source for this market will be information from NOAA, specifically the lowest 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.Recent National Weather Service observations at San Francisco International Airport recorded a daily minimum of 58°F on September 21, two degrees above the 1991–2020 normal of 56°F, amid persistent marine layer influence and patchy fog that moderated overnight cooling. Trader sentiment remains tightly split between the 54–55°F and 56–57°F bins because official lows can vary by a degree or two across downtown versus airport stations, depending on exact siting, wind patterns from the Pacific high, and the precise timing of the coldest hour near dawn. Historical September averages near 55.7°F and the absence of strong onshore flow or clear-sky radiational cooling kept probabilities from shifting decisively lower, while upcoming final climatological summaries may resolve any minor discrepancies between preliminary reports and verified daily extremes.
This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the San Francisco International Airport Station in degrees Fahrenheit on 21 Sep '26.
The resolution source for this market will be information from NOAA, specifically the lowest 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 lowest 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
$1,773End Date
Sep 21, 2026Market Opened
Sep 19, 2026, 7:29 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=ksfoResolver
0x69c47de9d...Outcome proposed: No
No dispute
Final outcome: No
Recent National Weather Service observations at San Francisco International Airport recorded a daily minimum of 58°F on September 21, two degrees above the 1991–2020 normal of 56°F, amid persistent marine layer influence and patchy fog that moderated overnight cooling. Trader sentiment remains tightly split between the 54–55°F and 56–57°F bins because official lows can vary by a degree or two across downtown versus airport stations, depending on exact siting, wind patterns from the Pacific high, and the precise timing of the coldest hour near dawn. Historical September averages near 55.7°F and the absence of strong onshore flow or clear-sky radiational cooling kept probabilities from shifting decisively lower, while upcoming final climatological summaries may resolve any minor discrepancies between preliminary reports and verified daily extremes.
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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