Fire incidents in houses and buildings can cause significant damage, endanger people, and pose risks to lives and property. Proper detection and alert systems are crucial for mitigating such risks and ensuring the safety of residents. This paper proposes a low-cost device equipped with an intelligent and reliable solution to detect and alert against fire hazards in residential and commercial buildings. The Raspberry Pi 3B+, a cost-effective single-board computer, serves as the central processing unit of the system. It integrates an advanced DHT22 sensor with the Adafruit library from Python, enabling highly efficient fire hazard detection. When the system detects temperature and humidity surrounding its area, it sends data to ThingSpeak, a cloud platform that displays data sent from the Raspberry Pi, and sends a warning to the registered email with the SMTP library. A key feature of this smart fire alarm system is its Internet connectivity, allowing for remote notification sending. Building owners or authorities can also receive real-time alerts. This facilitates timely responses and enables preventive measures to be taken when necessary.