How many bike trips started on the days in September, 2013 with the hottest temperature over 70 degrees Fahrenheit in the area where the zip code is 94107?
started on the days in September, 2013 refers to date LIKE'9%'AND date LIKE'%2013' hottest temperature over 70 degrees Fahrenheit refers to max_temperature_f>70;
SELECT COUNT(T1.id) FROM trip AS T1 INNER JOIN weather AS T2 ON T2.zip_code = T1.zip_code WHERE T2.date LIKE '9/%/2013' AND T2.zip_code = 94107 AND T2.max_temperature_f > 70