Warsaw, Poland's capital, experiences variable spring weather in mid-to-late April. The highest temperature on April 20 in Warsaw has ranged historically between 10°C and 20°C, making 15°C a moderate threshold for the season. This prediction market resolves based on official meteorological data from Poland's national weather service, which publishes the daily maximum temperature for Warsaw. The market's current odds of 17% for YES suggest the trading community assesses a relatively low probability that the day's high will reach or exceed 15°C, indicating traders expect temperatures to remain below this threshold. April 20 marks a transitional period in Warsaw's spring, with warming trends possible but cooler weather still common. Resolution is straightforward and verifiable through public weather records. The 24-hour trading volume of $2,030 reflects moderate interest in this short-duration weather market. Odds have remained relatively stable, suggesting consensus among traders on the likely temperature range.