湿度 and 湿気: humidity level and dampness
Distinguish humidity expressed as a degree from the noun for moisture or dampness.
A degree of humidity
湿度 (しつど) means the degree of humidity in the air. 「湿度を測りました」 means measuring humidity.
「昨日より湿度が高いです」 says humidity is higher than yesterday. 高い and 低い compare its level.
Dampness or moisture
湿気 (しっけ) means dampness or moisture. 「この部屋は湿気が多いです」 describes a room with much dampness.
「湿気を取るために窓を開けました」 says the window was opened to remove dampness. The purpose does not establish that the effect was sufficient.
A level versus a perceived condition
「湿度が下がりました」 describes a decrease in a measurable level. 「湿気を感じます」 reports sensing dampness.
「気温は同じでも、湿度は違います」 says humidity differs even when air temperature is the same. Do not merge temperature and humidity into one fact.
Does 「湿気を取るために窓を開けました」 establish that all dampness was removed?
Show the answer and why
No. It gives the purpose of opening the window; the result requires separate confirmation.