**2. Materials and Methods**

#### *2.1. Study Area and Data Collection*

Pusa is located in the Samastipur district of Bihar state, with latitude 25◦46 N and 86◦10 E. The location map of the study area is shown in Figure 1. Pusa lies 53 m above mean sea level in a hot sub-humid agro-ecological region in the middle of the Gangetic plain. The study area is located near the Burhi Ganadak river, a tributary of the Ganges river. The study area is famous for the Dr. Rajendra Prasad Central Agricultural University, a backbone of the study area's development. The average rainfall for Pusa is 1270 mm, of which 80% of the total rain falls during the monsoon season. The study area is fully covered by the area of the southwest monsoon, which starts in June and eases off in September. The maximum temperature varies from 32 to 38 ◦C during May and June. The minimum temperature varies from 6 to 9 ◦C during December and January. The main crops grown in the study area are wheat, maize, paddy, green gram, lentil, potato, and brinjal.

Meteorological data of the study area were gathered from the official "Dr. RPCAU" website (https://www.rpcau.ac.in, accessed on 13 April 2021), Pusa, Bihar. This included maximum and minimum temperatures (Tmax and Tmin, ◦C), relative humidity (RH-1, percent) at 7 a.m. and at 2 p.m. (RH-2, percent), wind speed (WS, km/h), bright sunshine hours (SSH, h) and daily pan evaporation (EPan, mm). For modeling pan evaporation, five years daily data set between the month 1 June to 30 September means that a total of 610 datasets have been used as input. The same is used for output [35].

Figure 2 displays the climate parameters determined in a box-and-whisker plot between June 2013 and September 2017 (i.e., five-year duration), indicating minimum, first quartile, median, third quartile, and maximum values.

**Figure 1.** Location map of the study area.

**Figure 2.** Box-and-whisker plot of climatic parameters in the study area.

The box-and-whisker plot shows that the relative humidity, measured at 7 a.m. and 2 p.m., respectively, demonstrates the highest variability among other meteorological parameters.
