Look! There's a 'c' in there. This 'c' is pronounced as /k/. The proper pronunciation is cli-MAC-tic.
Definition: Climactic is an adjective. The noun form is climax. Climax refers to the greatest point of intensity or interest.
The video: This is a scene from the Godfather, Part 2. The climactic scene in this movie is when Fredo is murdered.
Definition: Climatic is an adjective. The noun form is climate. Climate refers to the prevailing weather conditions of an area.
Example: The climatic conditions in the Ottawa area make it difficult to plan a camping trip 5 months in advance.