**High pressure building over the UK is the main driver behind current Polymarket odds favoring a 13–15°C minimum in London on September 20.** Official Met Office guidance and GFS/ECMWF runs show clearer skies overnight after a mild, cloudier 19 September, enabling greater radiative cooling under light northwesterly winds. This setup supports minimums near 11–14°C at standard sites such as Heathrow, with urban heat-island effects and exact station placement creating the narrow spread between the leading 14°C (37%) and 15°C (33.5%) outcomes. Model consensus remains tight for the short-range period, though small differences in boundary-layer moisture and wind speed can shift the overnight low by 1°C. Historical September minima average around 11–12°C, but the current synoptic pattern favors a milder value closer to the market’s clustered probabilities. Updated model runs and the Met Office’s evening briefing are the next key data points likely to influence trader positioning 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 London on September 20?
Lowest temperature in London on September 20?
14°C 46%
13°C 24%
15°C 24%
16°C 16%
NEW
NEW
Sep 20, 2026
9°C or below
2%
10°C
2%
11°C
2%
12°C
3%
13°C
24%
14°C
46%
15°C
24%
16°C
10%
17°C
5%
18°C
1%
19°C or higher
1%
14°C 46%
13°C 24%
15°C 24%
16°C 16%
NEW
NEW
Sep 20, 2026
9°C or below
$0 Vol.
2%
10°C
$0 Vol.
2%
11°C
$0 Vol.
2%
12°C
$18 Vol.
3%
13°C
$886 Vol.
24%
14°C
$845 Vol.
46%
15°C
$1,371 Vol.
24%
16°C
$286 Vol.
10%
17°C
$43 Vol.
5%
18°C
$28 Vol.
1%
19°C or higher
$10 Vol.
1%
This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the London City Airport Station in degrees Celsius on 20 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=eglc
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 Metric Units" button until the relevant table displays °C.
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 Celsius (eg, 9°C). 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.**High pressure building over the UK is the main driver behind current Polymarket odds favoring a 13–15°C minimum in London on September 20.** Official Met Office guidance and GFS/ECMWF runs show clearer skies overnight after a mild, cloudier 19 September, enabling greater radiative cooling under light northwesterly winds. This setup supports minimums near 11–14°C at standard sites such as Heathrow, with urban heat-island effects and exact station placement creating the narrow spread between the leading 14°C (37%) and 15°C (33.5%) outcomes. Model consensus remains tight for the short-range period, though small differences in boundary-layer moisture and wind speed can shift the overnight low by 1°C. Historical September minima average around 11–12°C, but the current synoptic pattern favors a milder value closer to the market’s clustered probabilities. Updated model runs and the Met Office’s evening briefing are the next key data points likely to influence trader positioning before resolution.
This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the London City Airport Station in degrees Celsius on 20 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=eglc
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 Metric Units" button until the relevant table displays °C.
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 Celsius (eg, 9°C). 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=eglc
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 Metric Units" button until the relevant table displays °C.
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 Celsius (eg, 9°C). 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 18, 2026, 12:29 AM ET
Volume
$3,486End Date
Sep 20, 2026Market Opened
Sep 18, 2026, 12:29 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=eglcResolver
0x69c47De9D...This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the London City Airport Station in degrees Celsius on 20 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=eglc
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 Metric Units" button until the relevant table displays °C.
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 Celsius (eg, 9°C). 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.**High pressure building over the UK is the main driver behind current Polymarket odds favoring a 13–15°C minimum in London on September 20.** Official Met Office guidance and GFS/ECMWF runs show clearer skies overnight after a mild, cloudier 19 September, enabling greater radiative cooling under light northwesterly winds. This setup supports minimums near 11–14°C at standard sites such as Heathrow, with urban heat-island effects and exact station placement creating the narrow spread between the leading 14°C (37%) and 15°C (33.5%) outcomes. Model consensus remains tight for the short-range period, though small differences in boundary-layer moisture and wind speed can shift the overnight low by 1°C. Historical September minima average around 11–12°C, but the current synoptic pattern favors a milder value closer to the market’s clustered probabilities. Updated model runs and the Met Office’s evening briefing are the next key data points likely to influence trader positioning before resolution.
This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the London City Airport Station in degrees Celsius on 20 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=eglc
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 Metric Units" button until the relevant table displays °C.
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 Celsius (eg, 9°C). 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=eglc
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 Metric Units" button until the relevant table displays °C.
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 Celsius (eg, 9°C). 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
$3,486End Date
Sep 20, 2026Market Opened
Sep 18, 2026, 12:29 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=eglcResolver
0x69c47De9D...**High pressure building over the UK is the main driver behind current Polymarket odds favoring a 13–15°C minimum in London on September 20.** Official Met Office guidance and GFS/ECMWF runs show clearer skies overnight after a mild, cloudier 19 September, enabling greater radiative cooling under light northwesterly winds. This setup supports minimums near 11–14°C at standard sites such as Heathrow, with urban heat-island effects and exact station placement creating the narrow spread between the leading 14°C (37%) and 15°C (33.5%) outcomes. Model consensus remains tight for the short-range period, though small differences in boundary-layer moisture and wind speed can shift the overnight low by 1°C. Historical September minima average around 11–12°C, but the current synoptic pattern favors a milder value closer to the market’s clustered probabilities. Updated model runs and the Met Office’s evening briefing are the next key data points likely to influence trader positioning 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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