When sourcing wind rain sensors, you must prioritize measurement accuracy and response time. For wind speed, look for sensors with an accuracy of ±3% or better and a starting threshold of <0.5m/s. For rain detection, ensure the sensor utilizes fritted glass or capacitive sensing technology rather than simple conductive strips to avoid false positives caused by oxidation. Additionally, verify the Ingress Protection (IP) rating, which should be at least IP65 or IP67 to ensure long-term durability in harsh outdoor environments.