Taipei's low season is 6-9月. While the weather isn't peak-perfect, the big wins are fewer crowds and lower prices. Attractions have no queues, hotels run 50-70% off peak rates, and flights often have 30-50% discounts. If you dislike crowds, low season can be the better choice.
Low-season caveats: ① Some attractions may have reduced hours or maintenance — check official sites before going; ② Weather is variable — bring rain gear and warm layers; ③ Seasonal events (like 灯会) may not run; ④ Restaurant and shop hours may shift. But core sights like 台北101 and 故宫博物院 stay open year-round.
Low-season perks: 士林夜市 at dawn is nearly empty — you can have it to yourself. Braised Rice spots have no queues. You can upgrade to a better hotel for less than a standard room in peak season. Watch for airline sales and lock in low fares early.