What are the days that had the smallest temperature range, and what was that range?
SELECT date ,  max_temperature_f - min_temperature_f FROM weather ORDER BY max_temperature_f - min_temperature_f LIMIT 1
SELECT date ,  max_temperature_f - min_temperature_f FROM weather ORDER BY max_temperature_f - min_temperature_f LIMIT 1
[{'date': '4/16/2015', 'max_temperature_f - min_temperature_f': 0}]