Recent forecast guidance from regional models indicates Cape Town will experience typical mid-May autumn conditions, with a strong Atlantic high-pressure ridge promoting light southerly winds and mostly clear skies that favor daytime highs near 21–22 °C. These temperatures sit just above the long-term May climatological average of 19–20 °C, reflecting a modest positive anomaly driven by reduced cloud cover and warmer-than-normal sea-surface temperatures offshore. Small differences in the precise strength and timing of the onshore flow, or the development of any shallow afternoon sea breeze, are the key variables separating the 21 °C and 22 °C outcomes that currently dominate trader sentiment. Updated runs from the South African Weather Service and global ensembles expected over the next 48 hours will likely tighten the range ahead of the Monday observation window.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedHighest temperature in Cape Town on May 18?
21°C 36%
22°C 34%
23°C 16%
20°C 9%
15°C or below
<1%
16°C
<1%
17°C
1%
18°C
1%
19°C
4%
20°C
9%
21°C
36%
22°C
34%
23°C
16%
24°C
4%
25°C or higher
1%
21°C 36%
22°C 34%
23°C 16%
20°C 9%
15°C or below
<1%
16°C
<1%
17°C
1%
18°C
1%
19°C
4%
20°C
9%
21°C
36%
22°C
34%
23°C
16%
24°C
4%
25°C or higher
1%
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the Cape Town International Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/za/matroosfontein/FACT.
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 to "Yes" until all data for this date has been finalized.
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.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.
Market Opened: May 16, 2026, 12:06 AM ET
Resolution Source
https://www.wunderground.com/history/daily/za/matroosfontein/FACTThe resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the Cape Town International Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/za/matroosfontein/FACT.
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 to "Yes" until all data for this date has been finalized.
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.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.
Resolution Source
https://www.wunderground.com/history/daily/za/matroosfontein/FACTRecent forecast guidance from regional models indicates Cape Town will experience typical mid-May autumn conditions, with a strong Atlantic high-pressure ridge promoting light southerly winds and mostly clear skies that favor daytime highs near 21–22 °C. These temperatures sit just above the long-term May climatological average of 19–20 °C, reflecting a modest positive anomaly driven by reduced cloud cover and warmer-than-normal sea-surface temperatures offshore. Small differences in the precise strength and timing of the onshore flow, or the development of any shallow afternoon sea breeze, are the key variables separating the 21 °C and 22 °C outcomes that currently dominate trader sentiment. Updated runs from the South African Weather Service and global ensembles expected over the next 48 hours will likely tighten the range ahead of the Monday observation window.
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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