Any great tips for removing hard water stains from exterior windows?

Try a little vinegar.

A 50/50 mix of vinegar and hot water.

Some vinegar and a rag should clear that up for you easily!

Vinegar will dissolve the minerals in the hardwater. Use a 50/50 vinegar water solution. You might want to use distilled water to eliminate the minerals.

Hello Bracha: Try dipping some paper towels in warm white vinegar and sticking them to the windows. Spray every now and again, with the vinegar, to keep the paper moist. Leave it this way for about 15 minutes and then use the paper towels to wipe the windows. I like using Viva paper towels as they are strong and reusable. You can rinse them out and wipe the windows a couple of times. That should do it, and you can even use a magic eraser to try to clean the windows.

Besides vinegar, which I tried and failed. I used Easy Off oven cleaner and it worked wonders.

A professional window cleaner who works cleans residential windows in my area told me to apply CLR to the outside window area. Best to not mix it with anything else. If the windows have been subjected to hard water from sprinklers over time, the outside glass may have become etched and nothing much is going to help with that problem.

Spray with vinegar to break up the deposits, you may need to soak as suggested by Betsy with paper towels.. Then use a scrub daddy (cold water) or other stiff sponge to remove it. After that, wipe down with a microfiber cloth that has be3en dampened with distilled water. Then follow up with a window cloth or newspaper. I like "SuperCloth". It's a bit pricey but well worth the investment. Mine are over 9 years old, still work like new. Make sure to clean on a cool day that isn't sunny to help avoid streaks.

Magic Eraser

This is how I clean my glass shower doors and they look fabulous. I imagine you could do the same on your windows with hard water stains. https://www.exquisitelyunremarkable.com/2020/04/how-to-clean-glass-shower-doors.html

This video guide should be able to help you out! https://www.youtube.com/watch?v=Oz0_Ge7G690

The guy that installed our pellet stove gave me a bottle of VERY hardcore glass cleaner meant specifically for soot etc. Its a little scary honestly lol but it cleans glass like nothing else. If you do a search for glass soot cleaner you can find it or something like it.

Hi Bracha! You can slice a lemon in half and rub it on the glass with a fair amount of pressure. The natural acidity of the lemon removes hard water stains with ease. Mop up the lemon juice left behind with a soft cloth or paper towel. Finish with a spray of glass cleaner and wipe it away with newspaper for a streak-free shine. Hope this helps!

Hi Bracha, hope this helps you out.

Take a little warm water and baking soda and mix them in a bowl to create a sort of paste for your windows. Then, use a cloth and scrub the hard water stains with the paste gently. The baking soda has an abrasive quality that will aid in removing the hard water stains on windows. For stubborn stains, use vinegar with backing soda and scrub. then rinse well and dry.