After a five week trip I finally returned home.
Yesterday (March 25th) was a clear, bright, and dry day in Austin Tx. Rather than the kind of smokey blue that is typical of my spring skies, the sky had a decent light blue color to it that did not whiten substantially towards the horizons.
Now it is typical that about this time of year, we start seeing deteriorating sky conditions due to the agricultural burning that is performed across the border in Mexico every year, so I beat that. The sky looked very good, and in line with my post on the topic, I wondered if this could be do to the dramatic decrease in vehicle traffic, which I theorize to be the greatest factor in light pollution other than the lights themselves due to the particulate matter in the atmosphere reflecting and absorbing light from the ground.
As my post suggested, I would take a baseline SQM-L reading and at 10:PM I did so. My measurement was 18.52 to 18.62 taken over several parts of the sky down to about 30 degrees away from zenith. This is considerably better than my average night where SQL readings can be in the 17s. This was close to Bortle 6 conditions, so noticeably darker than is typical for my location.
I did a nice two hour session and the sky was pretty cluttered with galaxies (though I am using an image intensified eyepiece) and I would say it was the best galaxy observing I have had from my back yard since I started using image intensifiers (which is to say the best ever from my back yard).
Now of course the evaluation is anecdotal at this point and it could have just been a fluke weather thing but the sky quality really did seem to be much better than I get on a typical spring night. This is why I wanted to do this though, and I will continue to do SQM measurements as a baseline until the ag burning makes that impractical.
The car traffic is maybe 50% of normal. The city went on Lockdown last night at midnight, and I expect that the traffic will be lighter today and since the day is forcast to be similar to yesterday (high in the 90s) I will be interested in seeing if there is any change, but I think I need 10 to 20 nights readings at this lowered activity to really be anything close to reliable.
Have fun out there.