**Recent forecasts from the National Weather Service and other models show San Francisco highs on September 4, 2026, centered in the upper 60s, with most guidance pointing to around 67°F under a returning marine layer after an early-season storm.** This places the daily maximum firmly in the 66–71°F range that dominates the market, with 70–71°F and 68–69°F together commanding over 70% of the implied probability. An unusually early September storm has driven temperatures 10–20°F below normal through Thursday, delivering light rain or drizzle and persistent cloud cover that suppressed daytime heating. As the front exits, gradual warming is expected Friday, but the classic marine layer—cool, moist air advected onshore by prevailing westerlies—will limit the rebound. Historical climatology supports this: the 1991–2020 average high for September 4 is 69.9°F, and recent years have frequently seen maxima in the mid-to-upper 60s when marine influence is strong. Key variables for traders include the precise timing of marine-layer clearance and any local microclimate differences across the city (e.g., warmer eastern neighborhoods versus cooler coastal zones). Updated model runs and the next NWS forecast discussion will likely refine the exact peak, keeping the 68–71°F outcomes as the clearest consensus while leaving room for modest upside or downside shifts.
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 4?
Highest temperature in San Francisco on September 4?
70-71°F 43%
68-69°F 28%
64-65°F 14%
66-67°F 11%
NEW
NEW
Sep 4, 2026
61°F or below
1%
62-63°F
6%
64-65°F
14%
66-67°F
11%
68-69°F
30%
70-71°F
43%
72-73°F
11%
74-75°F
4%
76-77°F
3%
78-79°F
2%
80°F or higher
2%
70-71°F 43%
68-69°F 28%
64-65°F 14%
66-67°F 11%
NEW
NEW
Sep 4, 2026
61°F or below
$0 Vol.
1%
62-63°F
$0 Vol.
6%
64-65°F
$20 Vol.
14%
66-67°F
$130 Vol.
11%
68-69°F
$7 Vol.
30%
70-71°F
$29 Vol.
43%
72-73°F
$60 Vol.
11%
74-75°F
$0 Vol.
4%
76-77°F
$0 Vol.
3%
78-79°F
$0 Vol.
2%
80°F or higher
$0 Vol.
2%
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 4 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.**Recent forecasts from the National Weather Service and other models show San Francisco highs on September 4, 2026, centered in the upper 60s, with most guidance pointing to around 67°F under a returning marine layer after an early-season storm.** This places the daily maximum firmly in the 66–71°F range that dominates the market, with 70–71°F and 68–69°F together commanding over 70% of the implied probability.
An unusually early September storm has driven temperatures 10–20°F below normal through Thursday, delivering light rain or drizzle and persistent cloud cover that suppressed daytime heating. As the front exits, gradual warming is expected Friday, but the classic marine layer—cool, moist air advected onshore by prevailing westerlies—will limit the rebound. Historical climatology supports this: the 1991–2020 average high for September 4 is 69.9°F, and recent years have frequently seen maxima in the mid-to-upper 60s when marine influence is strong.
Key variables for traders include the precise timing of marine-layer clearance and any local microclimate differences across the city (e.g., warmer eastern neighborhoods versus cooler coastal zones). Updated model runs and the next NWS forecast discussion will likely refine the exact peak, keeping the 68–71°F outcomes as the clearest consensus while leaving room for modest upside or downside shifts.
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 4 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 2, 2026, 7:56 AM ET
Volume
$246End Date
Sep 4, 2026Market Opened
Sep 2, 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 4 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.**Recent forecasts from the National Weather Service and other models show San Francisco highs on September 4, 2026, centered in the upper 60s, with most guidance pointing to around 67°F under a returning marine layer after an early-season storm.** This places the daily maximum firmly in the 66–71°F range that dominates the market, with 70–71°F and 68–69°F together commanding over 70% of the implied probability.
An unusually early September storm has driven temperatures 10–20°F below normal through Thursday, delivering light rain or drizzle and persistent cloud cover that suppressed daytime heating. As the front exits, gradual warming is expected Friday, but the classic marine layer—cool, moist air advected onshore by prevailing westerlies—will limit the rebound. Historical climatology supports this: the 1991–2020 average high for September 4 is 69.9°F, and recent years have frequently seen maxima in the mid-to-upper 60s when marine influence is strong.
Key variables for traders include the precise timing of marine-layer clearance and any local microclimate differences across the city (e.g., warmer eastern neighborhoods versus cooler coastal zones). Updated model runs and the next NWS forecast discussion will likely refine the exact peak, keeping the 68–71°F outcomes as the clearest consensus while leaving room for modest upside or downside shifts.
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 4 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
$246End Date
Sep 4, 2026Market Opened
Sep 2, 2026, 7:56 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=ksfoResolver
0x69c47De9D...**Recent forecasts from the National Weather Service and other models show San Francisco highs on September 4, 2026, centered in the upper 60s, with most guidance pointing to around 67°F under a returning marine layer after an early-season storm.** This places the daily maximum firmly in the 66–71°F range that dominates the market, with 70–71°F and 68–69°F together commanding over 70% of the implied probability. An unusually early September storm has driven temperatures 10–20°F below normal through Thursday, delivering light rain or drizzle and persistent cloud cover that suppressed daytime heating. As the front exits, gradual warming is expected Friday, but the classic marine layer—cool, moist air advected onshore by prevailing westerlies—will limit the rebound. Historical climatology supports this: the 1991–2020 average high for September 4 is 69.9°F, and recent years have frequently seen maxima in the mid-to-upper 60s when marine influence is strong. Key variables for traders include the precise timing of marine-layer clearance and any local microclimate differences across the city (e.g., warmer eastern neighborhoods versus cooler coastal zones). Updated model runs and the next NWS forecast discussion will likely refine the exact peak, keeping the 68–71°F outcomes as the clearest consensus while leaving room for modest upside or downside shifts.
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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