for the first time in several months
Expresses that something is happening after a gap of several months. Often used with 〜する or 〜だ to indicate the first occurrence in that period.
I met a friend for the first time in several months.
With the first rain in several months, the garden plants revived.
Standard kanji spelling using ヶ (small ke) for the counter.
Variant using 振り for ぶり; less common but acceptable.
Combination of 何 (what/how many), ヶ月 (counter for months), and ぶり (after an interval), with the question marker か. The ヶ is a simplified form of 箇.