A sky this yellowish color in springtime Israel quite often heralds a sandstorm. And one thing I learned in our first year in Israel was not to hang out laundry during a sandstorm, because it will dry with sand thoroughly embedded in the fabric, yes, dirtier than before being laundered. So, I'll postpone doing the wash until tomorrow or next week. It's also not a good day to open up the windows and certainly not to wash them.
Yes, there are two very good reasons not to wash windows before the Passover Holiday, even though lots of people like a totally sparkling clean house.
- The dirt on the windows is not the forbidden chametz.
- There's an excellent chance of sandstorms during the Jewish Months of Nissan and Iyar. And sandstorms really dirty/soil windows.