What role do hydrogen ions play in the electron transport chain high?

They are pumped across the mitochondrial inner membrane against their concentration gradient (to where their concentration is high); as the H+ ions flow back to where their concentration is low, they drive ATP synthase to form ATP

If the water vapor content stays the same and the temperature drops, then the relative humidity increases. its vise versa.if the water vapor content stats the same and the temperature rises, the relative humidity decreases. so, yes, i'd say that temperature and humidity have a strong relationship.