A multi-state, multi-disciplinary project is developing a comprehensive database of ammonia emissions from US poultry facilities. The influence of common management strategies and practical means of reducing ammonia (NH3) emissions are under study. The measurement of ammonia emissions under cold weather conditions from 11 broiler houses in Kentucky and Pennsylvania is described in this paper. Ammonia level was determined using electrochemical sensors; ventilation rate was estimated by monitoring runtime of the ventilation fans whose airflow rates were determined with a portable anemometer array, also known as the Fan Assessment Numeration System (FANS). Ammonia emission rates ranged from 0 to 0.92 g NH3 bird-1 d-1 or, expressed in terms of 500 kg animal units (AU), 0 to 607 g NH3 AU-1 d-1. Bird age ranged from 1 to 23 days. There was high variability for emission rates among the houses, even for houses on the same farm. Day to day variability (consecutive days) was less than house-to-house variability for the same time period. A better interpretation of the wide range of emissions rates can be made once characteristics of the litter, flock, and house management can be incorporated into data analysis.