The air is thick with humidity.

Meaning

The air is very humid and heavy.

Examples

• John: 'It's so sticky and uncomfortable today.'
• Alice: '<b>The air is thick with humidity.</b> I could really use some air conditioning.'
• John: '<b>The air is thick with humidity;</b> it's typical for this time of year.'
• Alice: 'I'm struggling to breathe. It feels so heavy.'