As meteorological observations evolve towards socialization and intelligence, the existing ground-based automatic weather stations can no longer meet the new demands due to their split design, large volume, high power consumption, and cost. This paper designs a multi-element modular automatic weather station. This weather station uses modular composition and digital sensor technology to flexibly observe meteorological elements such as temperature and humidity, air pressure, particulate matter 2.5, wind speed, and wind direction. This paper employs a band-pass filter designed with multi-channel negative feedback circuits to address the severe environmental interference affecting ultrasonic anemometers. This approach reduces the scale of the ultrasonic signal conditioning circuit and improves the quality of the ultrasonic pulse signals. Moreover, an adaptive filter algorithm with a sliding window size adjustment factor is introduced to reduce signal environmental interference. The experimental results show that the digital sensors used in the designed automatic weather station meet the observation requirements. Specifically, the wind measurement module has a maximum wind speed error of 14.8% and a maximum wind direction error of 11.78%. These figures indicate that the new weather station achieves high accuracy in wind measurements and demonstrates stable performance.