Recent National Weather Service guidance and ensemble model consensus point to a minimum temperature near 57–58°F for San Francisco on September 18, driven by typical late-summer onshore flow and a persistent marine layer that promotes radiational cooling under partly cloudy skies overnight. Light to moderate west winds, expected to diminish after midnight, will limit mixing and allow surface temperatures to approach the historical average low of 55.8°F while avoiding deeper fog or stronger advection that could push readings lower. Trader emphasis on the 58–59°F bin over adjacent ranges reflects confidence in this baseline pattern, tempered by minor uncertainty in exact cloud cover and wind timing that could add or subtract 1–2°F. Updated short-range model runs and overnight observations from local stations will provide the next key data points before resolution.
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?
62-63°F 37%
60-61°F 28%
56-57°F 24%
54-55°F 11%
NEW
NEW
Sep 18, 2026
51°F or below
5%
52-53°F
7%
54-55°F
11%
56-57°F
24%
58-59°F
38%
60-61°F
28%
62-63°F
37%
64-65°F
8%
66-67°F
11%
68-69°F
7%
70°F or higher
5%
62-63°F 37%
60-61°F 28%
56-57°F 24%
54-55°F 11%
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
$380 Vol.
24%
58-59°F
$91 Vol.
38%
60-61°F
$57 Vol.
28%
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 guidance and ensemble model consensus point to a minimum temperature near 57–58°F for San Francisco on September 18, driven by typical late-summer onshore flow and a persistent marine layer that promotes radiational cooling under partly cloudy skies overnight. Light to moderate west winds, expected to diminish after midnight, will limit mixing and allow surface temperatures to approach the historical average low of 55.8°F while avoiding deeper fog or stronger advection that could push readings lower. Trader emphasis on the 58–59°F bin over adjacent ranges reflects confidence in this baseline pattern, tempered by minor uncertainty in exact cloud cover and wind timing that could add or subtract 1–2°F. Updated short-range model runs and overnight observations from local stations will provide the next key data points before resolution.
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
$529End 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 guidance and ensemble model consensus point to a minimum temperature near 57–58°F for San Francisco on September 18, driven by typical late-summer onshore flow and a persistent marine layer that promotes radiational cooling under partly cloudy skies overnight. Light to moderate west winds, expected to diminish after midnight, will limit mixing and allow surface temperatures to approach the historical average low of 55.8°F while avoiding deeper fog or stronger advection that could push readings lower. Trader emphasis on the 58–59°F bin over adjacent ranges reflects confidence in this baseline pattern, tempered by minor uncertainty in exact cloud cover and wind timing that could add or subtract 1–2°F. Updated short-range model runs and overnight observations from local stations will provide the next key data points before resolution.
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
$529End 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 guidance and ensemble model consensus point to a minimum temperature near 57–58°F for San Francisco on September 18, driven by typical late-summer onshore flow and a persistent marine layer that promotes radiational cooling under partly cloudy skies overnight. Light to moderate west winds, expected to diminish after midnight, will limit mixing and allow surface temperatures to approach the historical average low of 55.8°F while avoiding deeper fog or stronger advection that could push readings lower. Trader emphasis on the 58–59°F bin over adjacent ranges reflects confidence in this baseline pattern, tempered by minor uncertainty in exact cloud cover and wind timing that could add or subtract 1–2°F. Updated short-range model runs and overnight observations from local stations will provide the next key data points 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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