Which station has the highest number of stores? Calculate the said station's average maximum temperature in February 2012.
station with highest number of stores refers to station_nbr where Max(Count(store_nbr)); station refers to station_nbr; in February 2012 refers to substring (date, 1, 7) = '2012-02'; average maximum temperature = Divide(Sum(tmax), 29)
SELECT CAST(SUM(T2.tmax) AS REAL) / 29 FROM ( SELECT station_nbr FROM relation GROUP BY station_nbr ORDER BY COUNT(store_nbr) DESC LIMIT 1 ) AS T1 INNER JOIN weather AS T2 ON T1.station_nbr = T2.station_nbr WHERE SUBSTR(T2.`date`, 1, 7) = '2012-02'