Recent National Weather Service forecasts and ensemble model guidance point to an overnight low near 57–58°F for San Francisco on September 18, driven by a persistent marine layer, light westerly onshore flow, and patchy fog that limits radiative cooling. This aligns with the recent pattern of upper-50s minima at SFO and the September climatological average of 55.8°F. The 58–59°F bin leads trader consensus because most guidance clusters there, while the 56–57°F range captures downside risk from stronger marine influence or clearer skies. Warmer outcomes remain possible only with unexpected offshore flow or model error, but current data show low probability of deviation. Updated NWS briefings and morning observations will refine resolution near the daily minimum.
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 18?
Lowest temperature in San Francisco on September 18?
58-59°F 65%
60-61°F 37%
62-63°F 37%
56-57°F 22%
NEW
NEW
Sep 18, 2026
51°F or below
5%
52-53°F
7%
54-55°F
11%
56-57°F
26%
58-59°F
57%
60-61°F
37%
62-63°F
37%
64-65°F
8%
66-67°F
11%
68-69°F
7%
70°F or higher
5%
58-59°F 65%
60-61°F 37%
62-63°F 37%
56-57°F 22%
NEW
NEW
Sep 18, 2026
51°F or below
$0 Vol.
5%
52-53°F
$0 Vol.
7%
54-55°F
$0 Vol.
11%
56-57°F
$285 Vol.
26%
58-59°F
$71 Vol.
57%
60-61°F
$0 Vol.
37%
62-63°F
$0 Vol.
37%
64-65°F
$0 Vol.
8%
66-67°F
$0 Vol.
11%
68-69°F
$0 Vol.
7%
70°F or higher
$0 Vol.
5%
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 18 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 forecasts and ensemble model guidance point to an overnight low near 57–58°F for San Francisco on September 18, driven by a persistent marine layer, light westerly onshore flow, and patchy fog that limits radiative cooling. This aligns with the recent pattern of upper-50s minima at SFO and the September climatological average of 55.8°F. The 58–59°F bin leads trader consensus because most guidance clusters there, while the 56–57°F range captures downside risk from stronger marine influence or clearer skies. Warmer outcomes remain possible only with unexpected offshore flow or model error, but current data show low probability of deviation. Updated NWS briefings and morning observations will refine resolution near the daily minimum.
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 18 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 16, 2026, 7:29 AM ET
Volume
$356End Date
Sep 18, 2026Market Opened
Sep 16, 2026, 7:29 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=ksfoResolver
0x69c47De9D...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 18 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 forecasts and ensemble model guidance point to an overnight low near 57–58°F for San Francisco on September 18, driven by a persistent marine layer, light westerly onshore flow, and patchy fog that limits radiative cooling. This aligns with the recent pattern of upper-50s minima at SFO and the September climatological average of 55.8°F. The 58–59°F bin leads trader consensus because most guidance clusters there, while the 56–57°F range captures downside risk from stronger marine influence or clearer skies. Warmer outcomes remain possible only with unexpected offshore flow or model error, but current data show low probability of deviation. Updated NWS briefings and morning observations will refine resolution near the daily minimum.
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 18 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
$356End Date
Sep 18, 2026Market Opened
Sep 16, 2026, 7:29 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=ksfoResolver
0x69c47De9D...Recent National Weather Service forecasts and ensemble model guidance point to an overnight low near 57–58°F for San Francisco on September 18, driven by a persistent marine layer, light westerly onshore flow, and patchy fog that limits radiative cooling. This aligns with the recent pattern of upper-50s minima at SFO and the September climatological average of 55.8°F. The 58–59°F bin leads trader consensus because most guidance clusters there, while the 56–57°F range captures downside risk from stronger marine influence or clearer skies. Warmer outcomes remain possible only with unexpected offshore flow or model error, but current data show low probability of deviation. Updated NWS briefings and morning observations will refine resolution near the daily minimum.
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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