Environmental monitoring at the RSPM Madiun is conducted manually, requiring staff to visit each room using various digital devices. This method is quite labor intensive and only allows problems to be detected during these rounds. To address this challenge, we developed JoMonitor, an IoT based platform that uses a State Change Detection algorithm to detect changes in conditions and notifies staff via Telegram and WhatsApp as soon as temperature and humidity exceed the permissible limits. JoMonitor consists of an ESP32 microcontroller and a DHT22 sensor. Data are collected every 15 seconds and sent to a dashboard built using the Laravel. Hysteresis ensures that minor fluctuations in temperature and humidity do not trigger false alarms, while delta logging ensures that only significant changes are detected. The system was evaluated through 20 Black Box Testing scenarios, each repeated 10 times, resulting in 200 test executions. The test results achieved 100% state transition detection accuracy, with notifications delivered within 2.8 seconds and an average system response time of 1.2 seconds. The delta logging approach reduces the database storage requirements by 95%, from 5,760 to 288 records per device per day. Overall, JoMonitor offers a reliable and efficient platform for monitoring the hospital environment that can reduce both notification overload and storage costs.