**Stable high-pressure conditions and clear skies are positioning 27°C as the leading outcome for Incheon/Seoul's daily maximum on September 20, 2026, with market-implied odds reflecting tight clustering around 26–28°C.** Official guidance from the Korea Meteorological Administration and multiple numerical weather models (including GFS and ECMWF runs) consistently forecast a high near 27°C under sunny to mostly clear conditions, light northeasterly to northerly winds of 5–10 km/h, and negligible precipitation risk. This aligns with the seasonal transition in late September, when the strengthening Siberian high promotes subsidence and drier air masses, moderating temperatures after summer while still allowing sufficient daytime insolation for highs in the mid-to-upper 20s°C. Recent 48-hour observations show stable surface pressures near 1020 hPa and dew points in the mid-teens Celsius, supporting efficient radiational cooling overnight but limited overnight recovery that keeps the diurnal range moderate. Model consensus shows low spread for peak values, with only minor variations tied to exact timing of maximum heating or boundary-layer mixing. Historical September climatology for Incheon places average daily maxima near 25–26°C, so the current setup represents slightly above-normal but not anomalous warmth. Traders appear to be weighting the official forecast heavily while allowing for small upside or downside revisions from the final model update before the 20th, explaining the combined ~98% probability mass on 25–28°C. No significant synoptic changes (such as frontal passages or typhoon influences) are expected in the next 48 hours that would shift the outlook.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedHighest temperature in Seoul (Incheon) on September 20?
Highest temperature in Seoul (Incheon) on September 20?
27°C 50%
26°C 28%
28°C 17%
25°C 5%
NEW
NEW
Sep 20, 2026
21°C or below
<1%
22°C
<1%
23°C
1%
24°C
1%
25°C
5%
26°C
28%
27°C
50%
28°C
17%
29°C
3%
30°C
4%
31°C or higher
1%
27°C 50%
26°C 28%
28°C 17%
25°C 5%
NEW
NEW
Sep 20, 2026
21°C or below
$261 Vol.
<1%
22°C
$135 Vol.
<1%
23°C
$320 Vol.
1%
24°C
$110 Vol.
1%
25°C
$247 Vol.
5%
26°C
$254 Vol.
28%
27°C
$1,078 Vol.
50%
28°C
$470 Vol.
17%
29°C
$148 Vol.
3%
30°C
$379 Vol.
4%
31°C or higher
$443 Vol.
1%
This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the Incheon Intl Airport Station in degrees Celsius on 20 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=rksi
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.**Stable high-pressure conditions and clear skies are positioning 27°C as the leading outcome for Incheon/Seoul's daily maximum on September 20, 2026, with market-implied odds reflecting tight clustering around 26–28°C.**
Official guidance from the Korea Meteorological Administration and multiple numerical weather models (including GFS and ECMWF runs) consistently forecast a high near 27°C under sunny to mostly clear conditions, light northeasterly to northerly winds of 5–10 km/h, and negligible precipitation risk. This aligns with the seasonal transition in late September, when the strengthening Siberian high promotes subsidence and drier air masses, moderating temperatures after summer while still allowing sufficient daytime insolation for highs in the mid-to-upper 20s°C.
Recent 48-hour observations show stable surface pressures near 1020 hPa and dew points in the mid-teens Celsius, supporting efficient radiational cooling overnight but limited overnight recovery that keeps the diurnal range moderate. Model consensus shows low spread for peak values, with only minor variations tied to exact timing of maximum heating or boundary-layer mixing. Historical September climatology for Incheon places average daily maxima near 25–26°C, so the current setup represents slightly above-normal but not anomalous warmth.
Traders appear to be weighting the official forecast heavily while allowing for small upside or downside revisions from the final model update before the 20th, explaining the combined ~98% probability mass on 25–28°C. No significant synoptic changes (such as frontal passages or typhoon influences) are expected in the next 48 hours that would shift the outlook.
This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the Incheon Intl Airport Station in degrees Celsius on 20 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=rksi
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 highest reading under the "Temp" column for all times on this day, available here: https://www.weather.gov/wrh/timeseries?site=rksi
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, 12:56 AM ET
Volume
$3,845End Date
Sep 20, 2026Market Opened
Sep 18, 2026, 12:56 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=rksiResolver
0x69c47De9D...This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the Incheon Intl Airport Station in degrees Celsius on 20 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=rksi
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.**Stable high-pressure conditions and clear skies are positioning 27°C as the leading outcome for Incheon/Seoul's daily maximum on September 20, 2026, with market-implied odds reflecting tight clustering around 26–28°C.**
Official guidance from the Korea Meteorological Administration and multiple numerical weather models (including GFS and ECMWF runs) consistently forecast a high near 27°C under sunny to mostly clear conditions, light northeasterly to northerly winds of 5–10 km/h, and negligible precipitation risk. This aligns with the seasonal transition in late September, when the strengthening Siberian high promotes subsidence and drier air masses, moderating temperatures after summer while still allowing sufficient daytime insolation for highs in the mid-to-upper 20s°C.
Recent 48-hour observations show stable surface pressures near 1020 hPa and dew points in the mid-teens Celsius, supporting efficient radiational cooling overnight but limited overnight recovery that keeps the diurnal range moderate. Model consensus shows low spread for peak values, with only minor variations tied to exact timing of maximum heating or boundary-layer mixing. Historical September climatology for Incheon places average daily maxima near 25–26°C, so the current setup represents slightly above-normal but not anomalous warmth.
Traders appear to be weighting the official forecast heavily while allowing for small upside or downside revisions from the final model update before the 20th, explaining the combined ~98% probability mass on 25–28°C. No significant synoptic changes (such as frontal passages or typhoon influences) are expected in the next 48 hours that would shift the outlook.
This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the Incheon Intl Airport Station in degrees Celsius on 20 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=rksi
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 highest reading under the "Temp" column for all times on this day, available here: https://www.weather.gov/wrh/timeseries?site=rksi
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
$3,845End Date
Sep 20, 2026Market Opened
Sep 18, 2026, 12:56 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=rksiResolver
0x69c47De9D...**Stable high-pressure conditions and clear skies are positioning 27°C as the leading outcome for Incheon/Seoul's daily maximum on September 20, 2026, with market-implied odds reflecting tight clustering around 26–28°C.** Official guidance from the Korea Meteorological Administration and multiple numerical weather models (including GFS and ECMWF runs) consistently forecast a high near 27°C under sunny to mostly clear conditions, light northeasterly to northerly winds of 5–10 km/h, and negligible precipitation risk. This aligns with the seasonal transition in late September, when the strengthening Siberian high promotes subsidence and drier air masses, moderating temperatures after summer while still allowing sufficient daytime insolation for highs in the mid-to-upper 20s°C. Recent 48-hour observations show stable surface pressures near 1020 hPa and dew points in the mid-teens Celsius, supporting efficient radiational cooling overnight but limited overnight recovery that keeps the diurnal range moderate. Model consensus shows low spread for peak values, with only minor variations tied to exact timing of maximum heating or boundary-layer mixing. Historical September climatology for Incheon places average daily maxima near 25–26°C, so the current setup represents slightly above-normal but not anomalous warmth. Traders appear to be weighting the official forecast heavily while allowing for small upside or downside revisions from the final model update before the 20th, explaining the combined ~98% probability mass on 25–28°C. No significant synoptic changes (such as frontal passages or typhoon influences) are expected in the next 48 hours that would shift the outlook.
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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