Questions & Answers about היום יש לחות גבוהה, ולכן אפילו בלי סערה אני מרגישה עייפה.
היום means today here. Hebrew often puts a time word near the beginning of the sentence to set the scene first.
A useful thing to know is that היום can also literally mean the day, depending on context. In this sentence, though, it clearly means today.
יש is the standard Hebrew way to say there is / there are or have in some contexts.
So:
- יש לחות גבוהה = there is high humidity
- literally, something like there exists high humidity
Hebrew does not normally use a separate verb like English is in this kind of sentence. So you do not say something equivalent to humidity is high here unless you build the sentence differently.