Design and Implementation of a Low-Cost Weather Monitoring System using ESP-NOW

In recent times, nearly every region worldwide faces significant risks due to climate change, making localized weather forecasting essential for the economic, agricultural, and humanitarian sectors. Existing weather systems largely rely on internet connectivity, which is unsuitable for remote areas. This paper presents a low-cost, real-time weather monitoring system that utilizes the ESP-NOW communication protocol, enabling operation without internet access. The system is based on the ESP32 S3 Wroom-1 microcontroller and integrates low-cost sensors to measure temperature, humidity, wind speed and direction, rainfall, and sunlight intensity with high accuracy. The system demonstrated an average temperature variation of $-8.54 \%$, a humidity variation of $-6.83 \%$, a significant $75 \%$ variation in rainfall detection and a wind speed variation of $-57.14 \%$ compared to publicly available Google data. These findings highlight the importance of localized weather monitoring in capturing specific changes that broader, general systems may overlook. Additionally, this system is energy-efficient, consuming only $28.8 \mathrm{~Wh} /$ day, and can operate effectively for 1.23 days on backup power, which is charged using renewable energy from solar panels. These features make the system an ideal solution for off-grid environments.