Current official guidance from the Finnish Meteorological Institute and other models shows a peak around 19–20°C on August 18 under southwesterly flow, partly cloudy skies, and Baltic Sea moderation that limits daytime heating. Ensemble spreads and recent runs introduce modest upside risk to 21°C if daytime insolation increases or warm advection strengthens slightly, while greater cloud cover or earlier frontal passage could cap the maximum at 19°C. Traders assign the highest probabilities to the 20–21°C outcomes because short-range model uncertainty at this lead time centers on boundary-layer mixing and local radiative effects rather than large-scale pattern shifts. Historical August maxima in Helsinki cluster near 18–20°C, providing context for the tight clustering of market-implied odds.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedHighest temperature in Helsinki on August 18?
Highest temperature in Helsinki on August 18?
20°C 40%
21°C 31%
19°C 19%
22°C 7%
NEW
NEW
Aug 18, 2026
15°C or below
<1%
16°C
<1%
17°C
2%
18°C
5%
19°C
19%
20°C
40%
21°C
31%
22°C
7%
23°C
2%
24°C
3%
25°C or higher
<1%
20°C 40%
21°C 31%
19°C 19%
22°C 7%
NEW
NEW
Aug 18, 2026
15°C or below
$31 Vol.
<1%
16°C
$142 Vol.
<1%
17°C
$146 Vol.
2%
18°C
$48 Vol.
5%
19°C
$183 Vol.
19%
20°C
$41 Vol.
40%
21°C
$74 Vol.
31%
22°C
$205 Vol.
7%
23°C
$88 Vol.
2%
24°C
$10 Vol.
3%
25°C or higher
$135 Vol.
<1%
This market will resolve based on the highest temperature recorded in the 'Daily Observations' table on Weather Underground, not the figure displayed in the 'Day High & Low' summary section; in the event of any discrepancy between the two, the Daily Observations table shall be the primary resolution source not the Day High & Low section.
This market will resolve to the temperature range that contains the highest temperature recorded at the Helsinki Vantaa Airport Station in degrees Celsius on 18 Aug '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day for the Helsinki Vantaa Airport Station, available here: https://www.wunderground.com/history/daily/fi/vantaa/EFHK.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve until the first data point for the following date has been published on the resolution source.
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.Current official guidance from the Finnish Meteorological Institute and other models shows a peak around 19–20°C on August 18 under southwesterly flow, partly cloudy skies, and Baltic Sea moderation that limits daytime heating. Ensemble spreads and recent runs introduce modest upside risk to 21°C if daytime insolation increases or warm advection strengthens slightly, while greater cloud cover or earlier frontal passage could cap the maximum at 19°C. Traders assign the highest probabilities to the 20–21°C outcomes because short-range model uncertainty at this lead time centers on boundary-layer mixing and local radiative effects rather than large-scale pattern shifts. Historical August maxima in Helsinki cluster near 18–20°C, providing context for the tight clustering of market-implied odds.
This market will resolve based on the highest temperature recorded in the 'Daily Observations' table on Weather Underground, not the figure displayed in the 'Day High & Low' summary section; in the event of any discrepancy between the two, the Daily Observations table shall be the primary resolution source not the Day High & Low section.
This market will resolve to the temperature range that contains the highest temperature recorded at the Helsinki Vantaa Airport Station in degrees Celsius on 18 Aug '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day for the Helsinki Vantaa Airport Station, available here: https://www.wunderground.com/history/daily/fi/vantaa/EFHK.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve until the first data point for the following date has been published on the resolution source.
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.
This market will resolve to the temperature range that contains the highest temperature recorded at the Helsinki Vantaa Airport Station in degrees Celsius on 18 Aug '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day for the Helsinki Vantaa Airport Station, available here: https://www.wunderground.com/history/daily/fi/vantaa/EFHK.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve until the first data point for the following date has been published on the resolution source.
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: Aug 16, 2026, 12:58 AM ET
Volume
$1,091End Date
Aug 18, 2026Market Opened
Aug 16, 2026, 12:58 AM ETResolution Source
https://www.wunderground.com/history/daily/fi/vantaa/EFHKResolver
0x69c47De9D...This market will resolve based on the highest temperature recorded in the 'Daily Observations' table on Weather Underground, not the figure displayed in the 'Day High & Low' summary section; in the event of any discrepancy between the two, the Daily Observations table shall be the primary resolution source not the Day High & Low section.
This market will resolve to the temperature range that contains the highest temperature recorded at the Helsinki Vantaa Airport Station in degrees Celsius on 18 Aug '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day for the Helsinki Vantaa Airport Station, available here: https://www.wunderground.com/history/daily/fi/vantaa/EFHK.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve until the first data point for the following date has been published on the resolution source.
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.Current official guidance from the Finnish Meteorological Institute and other models shows a peak around 19–20°C on August 18 under southwesterly flow, partly cloudy skies, and Baltic Sea moderation that limits daytime heating. Ensemble spreads and recent runs introduce modest upside risk to 21°C if daytime insolation increases or warm advection strengthens slightly, while greater cloud cover or earlier frontal passage could cap the maximum at 19°C. Traders assign the highest probabilities to the 20–21°C outcomes because short-range model uncertainty at this lead time centers on boundary-layer mixing and local radiative effects rather than large-scale pattern shifts. Historical August maxima in Helsinki cluster near 18–20°C, providing context for the tight clustering of market-implied odds.
This market will resolve based on the highest temperature recorded in the 'Daily Observations' table on Weather Underground, not the figure displayed in the 'Day High & Low' summary section; in the event of any discrepancy between the two, the Daily Observations table shall be the primary resolution source not the Day High & Low section.
This market will resolve to the temperature range that contains the highest temperature recorded at the Helsinki Vantaa Airport Station in degrees Celsius on 18 Aug '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day for the Helsinki Vantaa Airport Station, available here: https://www.wunderground.com/history/daily/fi/vantaa/EFHK.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve until the first data point for the following date has been published on the resolution source.
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.
This market will resolve to the temperature range that contains the highest temperature recorded at the Helsinki Vantaa Airport Station in degrees Celsius on 18 Aug '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day for the Helsinki Vantaa Airport Station, available here: https://www.wunderground.com/history/daily/fi/vantaa/EFHK.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve until the first data point for the following date has been published on the resolution source.
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
$1,091End Date
Aug 18, 2026Market Opened
Aug 16, 2026, 12:58 AM ETResolution Source
https://www.wunderground.com/history/daily/fi/vantaa/EFHKResolver
0x69c47De9D...Current official guidance from the Finnish Meteorological Institute and other models shows a peak around 19–20°C on August 18 under southwesterly flow, partly cloudy skies, and Baltic Sea moderation that limits daytime heating. Ensemble spreads and recent runs introduce modest upside risk to 21°C if daytime insolation increases or warm advection strengthens slightly, while greater cloud cover or earlier frontal passage could cap the maximum at 19°C. Traders assign the highest probabilities to the 20–21°C outcomes because short-range model uncertainty at this lead time centers on boundary-layer mixing and local radiative effects rather than large-scale pattern shifts. Historical August maxima in Helsinki cluster near 18–20°C, providing context for the tight clustering of market-implied odds.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated
Beware of external links.
Beware of external links.
Frequently Asked Questions