We are considering taking a northern lights cruise by P & o next year 2025. They have one in October and another in December. Has any one taken these cruises and kindly let us know their experience? We would prefer October but would that be good from the point of view of chances of seeing northern lights? Thanks for any help!

I took a similar cruise on Hurtigruten in March. The most important thing is to have clear skies, and there's no way to predict that so far in advance. On my cruise the skies were too cloudy and we never saw the lights, but I spent 3 nights in Tromso and I saw them 2 of the 3 nights there, on a Northern Lights tour.

Depending on where you live, you might be able to see them tonight from home.

As P_M says clear skies are needed. I have seen the Lights every Hurtigruten trip, but I have been lucky I guess.
You have to get far enough north. The sun is now very active, and should remain so for a year or so, but it is fickle.
December will probably be a lot colder, and days will be at their shortest for other activities. October will give you enough night and more daylight for excursions. Both months can be cloudy/rainy/snowy. But you only need one clear night.
Have you looked at a Hurtigruten or Havila trip instead of a P&O cruise?

Some Hurtigruten cruises offer a Northern Lights guarantee, which means you will get a free cruise if the lights are never visible on your cruise. Of course, that doesn't cover your cost of travel to the port.

I've taken 2 Hurtigruten cruises, one to Antarctica and one to Northern Norway. I would highly recommend them.