How can an increase in relative humidity affect visibility

[Rod Alexei]

Thanks in advance!

 

[BillTre]

Certainly it can in the extreme.
If relative humidity exceeds 100% then you will be getting condensation in the form of fog or rain which will reduce visibility.

It would not surprise me if there is an effect at lower RH, but I don't know for sure.

 

[Astronuc]

Relationship between Visibility and Relative Humidity, PM in terms of Hygroscopicity
http://adsabs.harvard.edu/abs/2008AGUFM.A11E0177J

Hygroscopicity plays a key role connecting those three variables. And constituent of aerosol is important factor in terms of hygroscopicity. Many experiments have been performed to find features of hygroscopicity with diverse kinds of constituents. Based on those preceding studies, we investigated how dominantly hygroscopicity influences on visibility.

Analysis of extinction properties as a function of relative humidity using a K-EC-Mie model in Nanjing
http://www.atmos-chem-phys-discuss.net/acp-2016-119/acp-2016-119.pdf