Spoiler warning is in effect, you have been warned.

Mitsuha is bored of her rural life and oddly wishes to be a boy in Tokyo, what follows is an out of body experience as Mitsuha switches bodies with a Tokyo boy named Taki, they somehow communicate through phone and written messages as both attempt to adjust to their new lives, this continues for some days until Taki stops switching into Mitsuha's body, with only clues of an Autumn Festival from Taki's last body switch, he tries to find the town of Itomori only to come to a tragic discovery that the town was destroyed by a fragmented comet and Mitsuha was killed with the entire town three years prior, not only was Taki switching bodies but switching times, praying to the shrine for a chance to prevent Mitsuha's death, he is able to switch again in order to evacuate the town before the comet arrives. They succeed only for Taki not to leave his name for Mitsuha to find him when the body switching ends for good, the ending several years later finishes with them crossing paths again in a very touching ending.
This film looks stunning, it's like a constant canvas of all the most beautiful images of Japan, the story is very fatally flawed.
If this was just a simple body switch story, I honestly think it would've still been highly acclaimed but adding a time travel element just muddied the waters too much, it's a plot point that cannot easily be done without serious plot holes and here are just a couple.
1. Considering how often they use phones, on all phones with any screen the first thing you see when you look at it is the current time and date, how they didn't click that it was a different time is beyond me.
2. A disaster on the scale of what happened in Itomori would be world news and would resonate in Japan for much longer, Taki should've witnessed it heck even felt it as it would likely cause a nation wide quake. There's no way he wouldn't know, the gap is only three years he wasn't that young when it happened.
The plot is so over complicated and melodramatic that the first half of the film quickly gets overshadowed by everything that happens in the second half, this only gets more noticeable and exhausting with every viewing.
Dubbing is fine, stick with Japanese for full effect.
Makoto Shinkai even said himself that the film was rushed and under funded, you can only imagine what could've been if he was allowed what he needed to finish it.
Final Verdict: A beautiful canvas like world let down by over complicated writing riddled with plot holes and melodrama.