Explanation:

- To begin with (Option 1): This phrase usually starts a narrative or explanation, making it irrelevant here since the sentence does not introduce a sequence of thoughts.

- By the way (Option 2): This phrase introduces a related but non-critical point, which doesn’t fit well in the context of describing wind conditions.

- First of all (Option 3): This is used to list items or ideas in order of importance; it’s not suitable for this sentence as it doesn’t enumerate points.

- Speaking of (Option 4): This ties directly back to a topic already mentioned, which fits best here as it seems to continue a conversation about the weather.