Official Met Office hourly observations from London stations, including Greater London sites, confirm the highest temperature on April 17 reached 18°C, peaking around mid-afternoon amid persistent cloud cover and light winds that capped daytime warming. This aligns with pre-event forecast model consensus from the UK Meteorological Office, predicting mild highs of 16–18°C after an unusually warm early April spell featuring 26°C peaks. Trader consensus at 100% implied probability for 18°C reflects verified observational data from authoritative stations like those near Heathrow and City Airport, backed by real capital in the market. Realistic challenges would require rare post-resolution data revisions from official sources, though current records show no discrepancies across proximal monitoring points.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedHighest temperature in London on April 17?
Highest temperature in London on April 17?
18°C 100.0%
12°C or below <1%
13°C <1%
14°C <1%
$213,263 Vol.
$213,263 Vol.
12°C or below
No
13°C
No
14°C
No
15°C
No
16°C
No
17°C
No
18°C
Yes
19°C
No
20°C
No
21°C
No
22°C or higher
No
18°C 100.0%
12°C or below <1%
13°C <1%
14°C <1%
$213,263 Vol.
$213,263 Vol.
12°C or below
No
13°C
No
14°C
No
15°C
No
16°C
No
17°C
No
18°C
Yes
19°C
No
20°C
No
21°C
No
22°C or higher
No
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 London City Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/gb/london/EGLC.
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: Apr 15, 2026, 12:05 AM ET
Resolution Source
https://www.wunderground.com/history/daily/gb/london/EGLCResolver
0x69c47De9D...Outcome proposed: No
No dispute
Final outcome: No
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 London City Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/gb/london/EGLC.
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/gb/london/EGLCResolver
0x69c47De9D...Outcome proposed: No
No dispute
Final outcome: No
Official Met Office hourly observations from London stations, including Greater London sites, confirm the highest temperature on April 17 reached 18°C, peaking around mid-afternoon amid persistent cloud cover and light winds that capped daytime warming. This aligns with pre-event forecast model consensus from the UK Meteorological Office, predicting mild highs of 16–18°C after an unusually warm early April spell featuring 26°C peaks. Trader consensus at 100% implied probability for 18°C reflects verified observational data from authoritative stations like those near Heathrow and City Airport, backed by real capital in the market. Realistic challenges would require rare post-resolution data revisions from official sources, though current records show no discrepancies across proximal monitoring points.
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