I live in the dark sky city of Flagstaff, AZ, the 1st International Dark Sky City. Lately, the skies seem brighter than usual.
I have a Sky Quality Meter and have been measuring the darkness over the last few days and it has been around 20.7. There is no moon. Just a few months ago, I measured the sky at 21.15-21.2. That is the darkest I have measured. It isn't always that dark but the sky appears brighter now so that is why I have been measuring it the last few days.
Why do you think it is noticeably brighter? It is not very humid so there isn't a lot of moisture in the air but maybe it is more humid than my darker measurements. Would that make such a large difference? Could more homes have their lights on? Dirt in the air?
I am concerned and want it dark again. We have some new street lights installed across the city, but they are not supposed to affect the sky. They are aimed downwards and the city worked with the Lowell Observatory to be sure the new lights would not make the sky brighter.
Thanks for any ideas, Kent