There is a 'Sampling Bias' risk. The NOAA Time Series source typically relies on METAR aviation reports, which are discrete snapshots (usually hourly). The 'highest reading' under the 'Temp' column captures only these specific timestamps, potentially missing the true continuous daily maximum temperature that occurs between reports. Consequently, the settlement value is often slightly lower than the official daily high reported by local meteorological agencies. Additionally, users must ensure the NOAA interface displays Taiwan Local Time (UTC+8) rather than UTC to align with the 'March 23' date requirement.

This is a niche weather prediction market. While weather forecasting is common, betting on the precise temperature for a specific airport (RCTP), date, and granular data source (NOAA Time Series) qualifies as a moderately exotic or novelty market.

From March 20 to March 21, 2026, the price of the 26°C option surged from 26c to 39c, while 27°C maintained a high valuation above 30c. The reason is the market confirmed the warm front trend, completely abandoning the previous '22°C or below' expectation (which crashed from 40c to 1.5c). From March 19 to March 20, 2026, the price of the 27°C option rose from 17c to 36c, as the CWA updated the Taipei regional forecast, causing an initial aggressive reaction to the warming trend.

Significant divergence exists. Polymarket traders are currently pricing 27°C at ~30% probability, with premiums on 28°C+. However, specific forecasts for the resolution location (Taoyuan Airport/Dayuan District) show highs of 24°C (Google) or 25°C (CWA), with only AccuWeather touching 26°C. The market pricing is biased significantly 'too hot,' lagging behind the specific location's cooler data.