[upstate]

Has anyone noticed this, I was told it could be the spray from the pest control companies. If true, I’m not sure what the answer is.

[retiredguy123]

Check to see if your sprinklers are spraying water on the wall. The irrigation water will cause a stain.

[villagetinker]

Try sno-cap (ACE hardware), mix per instructions, use a garden sprayer to apply, wait a few minutes and use a hose to wash off.

[LAFwUs]

Roof shingles can be another cause.
Newer roofs will leach color for a while. If you have no gutters on a particular side of the house, that tinted run off could be the cause. Not saying it "IS", but could be.