If I were in Hawaii and dropped a bowling ball in a bucket of water which is 45 degrees F, and dropped another ball of the same weight, mass, and size in a bucket at 30 degrees F, both of them at the same time, which ball would hit the bottom of the bucket first? Same question, but the location is in Canada?

Both balls are the same weight, mass, and size. Gravity accelerates all objects equally regardless of temperature. The ball in the warmer water (45°F) would hit bottom first because liquid water exists at 45°F, but at 30°F water would be frozen (ice), so the second ball wouldn't fall through at all. In Canada (colder climate), the 30°F bucket would be frozen solid.