Recent forecasts for San Francisco on September 4 point to overnight lows near 55–58°F amid a weakening marine layer driven by the North Pacific High and the cold California Current. Model consensus shows partly cloudy conditions with limited onshore flow, but small differences in marine layer depth, wind direction, or residual moisture from recent drizzle could shift the minimum by several degrees. Historical early-September averages hover around 56°F, yet the tight clustering of market-implied odds across 54–59°F ranges reflects genuine forecast uncertainty in how effectively the layer suppresses radiational cooling overnight. Upcoming National Weather Service updates will refine these variables ahead of 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 4?
47°F or below 59%
66°F or higher 58%
52-53°F 49%
60-61°F 49%
47°F or below
59%
48-49°F
42%
50-51°F
43%
52-53°F
49%
54-55°F
32%
56-57°F
24%
58-59°F
31%
60-61°F
49%
62-63°F
49%
64-65°F
49%
66°F or higher
58%
47°F or below 59%
66°F or higher 58%
52-53°F 49%
60-61°F 49%
47°F or below
59%
48-49°F
42%
50-51°F
43%
52-53°F
49%
54-55°F
32%
56-57°F
24%
58-59°F
31%
60-61°F
49%
62-63°F
49%
64-65°F
49%
66°F or higher
58%
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 2, 2026, 7:29 AM ET
Resolution Source
https://www.weather.gov/wrh/timeseries?site=ksfoResolver
0x69c47De9D...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.
Resolution Source
https://www.weather.gov/wrh/timeseries?site=ksfoResolver
0x69c47De9D...Recent forecasts for San Francisco on September 4 point to overnight lows near 55–58°F amid a weakening marine layer driven by the North Pacific High and the cold California Current. Model consensus shows partly cloudy conditions with limited onshore flow, but small differences in marine layer depth, wind direction, or residual moisture from recent drizzle could shift the minimum by several degrees. Historical early-September averages hover around 56°F, yet the tight clustering of market-implied odds across 54–59°F ranges reflects genuine forecast uncertainty in how effectively the layer suppresses radiational cooling overnight. Upcoming National Weather Service updates will refine these variables ahead of 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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