It really depends on the purpose of the trip. For example, when I lived in a cold climate a trip to a warm tropical one in the winter was ALL about getting some sun and warmth..to arrive and stay in a constant downpour the whole time did sort of ruin the trip. If I am camping, weather can ruin the trip.

However, if I am on business, it makes very little difference what the weather is so long as it does not interfere with my getting to where I need to go. I remember being snowed out by a blizzard in Co. Springs a few years ago and unable to get to the branch office. I remember being late for a meeting in St. Louis due to a heavy downpour and roads being flooded out in places.

But if crappy weather is generally expected in a specific place due to the normal climate, for example rain in London, it makes no differance.

For me, the biggest factor in ruining or making a trip great is the quality of the hotel.