1. Insufficient or inaccurate meteorological observation data: Weather forecast depends on accurate meteorological observation data, including temperature, humidity, wind power and precipitation. If these data are insufficient or inaccurate, it will affect the accuracy of weather forecast.

2. The influence of island topography and seasonal changes: Pingtan is located in an island, affected by marine climate and topography, and the weather changes are complex, which increases the difficulty of weather forecasting. In addition, seasonal changes will also lead to different weather changes. Weather factors such as typhoons in summer may have an impact on the weather forecast.

3. Limitations of weather forecasting technology: Although modern weather forecasting technology has made great progress, there are still some limitations. The accuracy of meteorological forecast is influenced by many factors, including the acquisition of meteorological data, the accuracy of meteorological model and the calculation ability.

Therefore, the inaccurate weather forecast in Pingtan may be the result of a combination of factors. In order to improve the accuracy of weather forecast, it is necessary to continuously improve meteorological observation techniques and methods and strengthen the in-depth study of meteorological changes in Pingtan area.