I want to go back to Japan so bad! Lucky you! A google search says the average temp in March is 62. I've never been on a cruise so can't help you with clothing. I'm going to England soon and am prepared for their average/last year's and hotter than normal temps, just in case.

Kathsgrdn thanks. I am making an assumption Japan it is like here in the Spring plus the breeze from the ships movements. Meaning warm one hour and feeling cold the next. Be certain to take a broad brimmed hat. I watch a couple of YT magnet fishing groups and the people living there just are not used to the temperatures and most places apparently do not have ac.

Much of Japan has very hot and humid summers. Since it's island based, climate ranges have more of a maritime influence that the middle of the US. Information about climates where you will be should be available from the internet. If you want an indication, Japan, located on the western side of a Northern Hemisphere ocean, is influenced by warm ocean currents coming up from the Equator as is the Eastern US. Southern Japan seems to have a similar latitude as the Carolinas/Virginia area so coastal locations in these US places should be similar.

Ducted heating and air conditioning is not common outside North America. The minisplit AC device was invented in Japan and several Japanese companies have been the largest producers of same - Mitsubishi, Fujitsu, Daikin, and Panasonic are examples. You'll see them (often mounted to the outside of buildings) all over Japan, other parts of Asia, and the Mediterranean. Minisplits are becoming more common in the US because they're more energy efficient.

In the past I traveled often for business trips and also lived and worked in the Osaka area over a year. The latitude of that region is close to that of central North Carolina so their temperatures are quite similar although with higher humidity. It will be warmer further south of Osaka if that where the cruise line starts.

I did make a mistake the first cruise starts March 15 not March 14 so I am not concerned about summer time temperatures. The cruise starts and ends in Yokohama. When it was first mentioned it was a 14 day cruise with more stops but depending on how the season is it should be near the cherry blossom bloom time.

Not certain if this link will post but this is where it goes.

Cruise Details - 9-Day Kyushu Spring Flowers - Princess Cruises

There’s a TripAdvisor Cruises Forum where you might get answers from people who've been on such cruises:

TripAdvisor Cruises Forum

Also Cruise Critic:

Cruise Critic

I've been to Japan a few times and it was always very pleasant in the Narita airport no matter the time of year :-p

Thank you, Lone Jack. Sounds like I can leave a heavier coat behind and only take something light for the ship as I go on deck. Expensive but I suspect the ship has stores which carry coverups for that time of year. Planning on only a small suitcase and/or just a carryon if the trip does happen.

I believe he's joking, mentioning a constant temperature inside the airport. Something to be found indoors in public buildings with functioning HVAC systems every day everywhere.

As was I, Elmer except for the last sentence.

You can probably stay warm wearing a sweater and put on a light or medium weight coat/jacket as needed. Hopefully the weather is warm early this spring so you can participate in Hanami along side the locals in further south of the islands.

I would be thinking on the lines of a light weight windbreaker.

I freeze in windbreakers and always have. I have even some that are lined with various fabrics. I thought that was all I would need on the San Juan Ferry and boy was I wrong.

I found that one of those packable down jackets, along with a wool sweater, and a thin cotton blend hoodie, worked very well to mix & match/layer with base layer T shirt on my March trip with quite variable temperatures (mostly on the cool to cold-in-the-AM side - desert climate.) Something to cover my ears was needed also, once or twice - one of those light, thin polypropylene types.

Thank your raee. Will need to do some shopping and I would not be looking for wool but was your sweater tight knit or a loose one. I will need to purchase a puffer jacket to see if my body has changed enough that it feels warm in one. I have had a couple but the way the stitching was the one I had let in a lot of cold. Hopefully the stitching has changed.