Don’t pursue the “best all year round” answer, use seasonal and weather boundaries to plan a suitable trip.
Spring: A comfortable alternative for rainy days
Spring is a good time to organize cultural observations around tea, flowers and ancient cities, but spring rains may change walking and mountain activities. Don’t bet your trip on a sunny day. Museums, houses, and cultural exhibitions can be an equally informative day.

Summer: Avoid walking hard at noon, watch the island warning first
Schedule hydration, rest, and indoor visits during the summer. For island, water and mountain activities, pay attention to information about typhoons, short-term heavy rainfall and sailing closures, and do not insist on entering risk areas just because they are "already booked".
Autumn: Suitable for slow walking, but also prepare for the holidays in advance
You can combine landscape tours, ancient city walks and coastal scenery, but tickets, vehicles and accommodation during National Day and other holidays should be checked in advance. Popular destinations can reduce cross-region movement and give each area a more complete time.
Winter: Southern Fujian humanities and mountain warmth should be considered separately
Cities such as Xiamen and Quanzhou can organize slow tours around buildings, restaurants and streets; mountainous areas such as Wuyi Mountain should pay attention to temperature differences and humidity. Seasons only provide general directions, and specific travel still depends on the weather on that day.
Turn the stories you read into your own journey.
Arrange a suitable Fujian route based on your dates, interests and traveling companions.