The month of September is dedicated to Our Lady of Sorrows, whose memorial the Church celebrates on September 15. September falls during the liturgical season known as Ordinary Time, which is represented by the liturgical color green.

During September, as in all of Ordinary Time (formerly known as Time After Pentecost), the Liturgy does not focus on one particular mystery of Christ, but views the mystery of Christ in all its aspects. We follow the life of Christ through the Gospels, and focus on the teachings and parables of Jesus and what it means for us to be a follower of Christ. During Ordinary Time we can concentrate more on the saints and imitate their holiness as Christ's followers. This month the main liturgical feasts are St. Gregory the Great (September 3), St. Peter Claver (September 9), Holy Name of Mary (September 12), St. John Chrysostom ( September 13), Exaltation of the Holy Cross (September 14), Sts. Cornelius and Cyprian (September 16), St. Robert Bellarmine (September 17), St. Januarius (September 19), St. Andrew Kim and Companions (September 20), St. Matthew (September 21), Sts. Cosmas and Damian (September 26), St. Pio (September 23), St. Vincent de Paul (September 27), and St. Jerome (September 30). The feasts of the Birth of Mary (September 8), Our Lady of Sorrows (September 15), and Sts. Michael, Gabriel and Raphael (September 29) are superseded by the Sunday liturgy.

Since man is both a spiritual and physical being, the Church provides for the needs of man in his everyday life. The Church's liturgy and feasts in many areas reflect the four seasons of the year (spring, summer, fall and winter). The months of August, September, October and November are part of the harvest season, and as Christians we recall God's constant protection over his people and give thanksgiving for the year's harvest. The September Ember Days were particularly focused on the end of the harvest season and thanksgiving to God for the season. Ember Days were three days (Wednesday, Friday and Saturday) set aside by the Church for prayer, fasting and almsgiving at the beginning of each of the four seasons of the year. The ember days fell after December 13, the feast of St. Lucy (winter), after the First Sunday of Lent (spring), after Pentecost Sunday (summer), and after September 14, the feast of the Exaltation of the Holy Cross (fall). These weeks were known as the quattor tempora, the "four seasons." Since the late 5th century, the Ember Days were also the preferred dates for ordination of priests. So during these times the Church had a threefold focus: (1) sanctifying each new season by turning to God through prayer, fasting and almsgiving; (2) giving thanks to God for the various harvests of each season; and (3) praying for the newly ordained and for future vocations to the priesthood and religious life. Since the reorganization of the Roman calendar in 1969 after the Second Vatican Council, Ember Days are still retained in principle, but how and when they are to be observed is at the discretion of each country's Episcopal Conference. There is no longer set Mass readings for the Ember Days in the Ordinary Rite. Another harvest feast is September 29, the Feast of the Archangels Michael, Gabriel and Raphael. Before the revision of the calendar, this used to be only the feast of St. Michael. In many countries this day was referred to as "Michaelmas" and is celebrated with traditional foods and customs. By Jennifer Gregory Miller, 2003.