Final answer:
The punctuated correctly, showing possession with an apostrophe for the two cities' weather. It should begin with a capitalized 'The', unless it's part of a larger sentence or title. The use of 'weather' pertains to outside conditions such as temperature and sunshine.
Step-by-step explanation:
The sentence "The two cities' weather is always warm." is correct in terms of punctuation. The apostrophe correctly shows possession for the two cities, and therefore, the weather which is being described pertains to both cities in question.
However, unless this sentence is a part of a larger sentence or a title, it should begin with a capital 'T' for 'The' to be completely correct. When discussing weather, we refer to the outside conditions such as temperature and whether it's sunny or cloudy. It's important to distinguish this from "whether," which is a conjunction used to introduce choices.
Warm weather is often a topic in literature and conversation to describe pleasant climates or notable environmental changes. For example: "The Gulf Stream gave us warm blue days again, but pale, like sad memories." In this example, the phrase 'warm blue days' evokes a certain atmosphere and feeling.