The advancement of applications in Internet-of-Things (IoT) has taken its share in smart farming and smart agriculture. The devices used in IoT can sense, process and communicate the data across the Internet to the user. These devices are easily accessible by unauthenticated users. To secure the data collected by the smart device, it is essential to have security features imbibed. Traditionally, the security scheme developed by various researchers have been evaluated for different attacks using simulation tools like AVISPA, ProVerif. But, it is essential to check the device security by performing a real-time attack. In this research, real-Time attack strategies are shown for an IoT based weather monitoring application that are essential for smart agricultural production. Attacks such as man-in-The-middle (MITM) attack, replay attack and denial of service(DoS) attacks are performed on the weather monitoring setup. By running Elliptic Curve Cryptography (ECC) based security schemes on the devices, the attacks are performed to analyze the system response towards the real-Time attacks for various ECC based solutions.