# An ANN Model Trained on Regional Data in the Prediction of Particular Weather Conditions
## 4 Results
### Comparison of the Results Obtained by MLP, Two Other ML Models, and the Weather Service  
To check the effectiveness of the forecast obtained with the use of our MLP model compared to the accuracy of the weather service forecast, the obtained results of the forecast of the selected weather conditions by the MLP model for the next day were compared with the results of the weather service forecast for 2018 for the city of Szczecin. The archival data of weather service forecasts especially for the city of Szczecin provided by OpenWeather ([[https://openweathermap.org/](https://openweathermap.org/)]([https://openweathermap.org/](https://openweathermap.org/)) accessed on 29 April 2021) are available free of charge on the website under the link ([[https://www.ekologia.pl/pogoda/olska/zachodniopomorskie/szczecin/archiwum,zakres,01-01-2019_31-01-2019,calosc](https://www.ekologia.pl/pogoda/olska/zachodniopomorskie/szczecin/archiwum,zakres,01-01-2019_31-01-2019,calosc)]([https://www.ekologia.pl/pogoda/olska/zachodniopomorskie/szczecin/archiwum,zakres,01-01-2019_31-01-2019,calosc](https://www.ekologia.pl/pogoda/olska/zachodniopomorskie/szczecin/archiwum,zakres,01-01-2019_31-01-2019,calosc)) accessed on 29 April 2021). We used archived data from 1 January 2018 to 31 December 2020. OpenWeather is an open-source weather data service that requires no license to download. OpenWeather's API provides a user-friendly way to download data for a selected city without having to enter the geographic coordinates, provides current and archived data \begin{table}
\begin{tabular}{l c} \hline \hline
**Predicted Condition** & **Excluded Variables** \\ \hline Maximum daily temperature & Daily sum of precipitation, mean daily wind speed, mean daily general cloud cover \\ Minimum daily temperature & Daily sum of precipitation, mean daily wind speed, mean daily general cloud cover \\ Mean daily atmospheric pressure & Mean daily relative humidity, maximum daily temperature, daily dew duration \\ Mean daily wind speed & Mean daily relative humidity, maximum daily temperature, mean daily general cloud cover \\ Daily sum of precipitation & Mean daily relative humidity, mean daily general cloud cover, mean daily wind speed \\ \hline \hline \end{tabular}
\end{table} 
Table 7: The training variables excluded from the model based on the variable selection. \begin{table}
\begin{tabular}{l c c} \hline \hline
**Inputs Out** & **Training MSE** & **Testing MSE** \\ \hline Mean daily temperature & 7.0542 & 7.6108 \\ Daily dew duration & 6.6200 & 6.9386 \\ Mean daily atm. pressure & 6.5968 & 7.0749 \\ Min. daily temp. at ground level & 6.4327 & 6.8041 \\ Mean daily relative humidity & 6.4202 & 6.7626 \\ Maximum daily temperature & 6.3103 & 6.8945 \\ Minimum daily temperature & 6.2282 & 6.6756 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: The results of the sensitivity analysis for the prediction of the maximum daily temperature. for 40 years back, and includes Polish diacritical marks, which is important for the location for which our study was conducted. The API of this service is also recommended by the Polish government service ([[https://www.gov:pl/web/popcwsparcie/standard-api-dla-u-dostepniania-danych](https://www.gov:pl/web/popcwsparcie/standard-api-dla-u-dostepniania-danych)]([https://www.gov:pl/web/popcwsparcie/standard-api-dla-u-dostepniania-danych](https://www.gov:pl/web/popcwsparcie/standard-api-dla-u-dostepniania-danych)) accessed on 1 March 2021). Table 16 in Appendix E presents sample values of the parameters forecasted from 1 January 2018 to 31 December 2020. The predicted parameters are listed below:  
* Maximum daily temperature in \({}^{\circ}\)C.
* Minimum daily temperature in \({}^{\circ}\)C.
* Mean daily atmospheric pressure at station level in hPa. * Mean daily wind speed in m/s. * Daily sum of precipitation in mm.