High readings in Stockholm, Sweden

Last evening I had 25 readings of 173 to 241 CPM from 19:04 UTC to 19:28 UTC.
Before and after these readings the level are normal.
The reader is placed ouside on a balcony and the only possible visitor may be the neighbors cat, which I hope is more or less clean from radioactivity.

Any thinkable explanation for this high readings during this period?

Carl

a bad/dirty gm tube commection has caused this kind of problem for me lately...

Don't rule out the cat. One of our members in Georgia, USA has a cat that underwent radiation therapy: http://www.radmon.org/index.php/kunena/station-detections/105-high-readings-in-ga#558]

Aside from dirty/loose connections and a radioactive cat, I wonder about wind direction. Can you find out the prevailing wind direction that night?
What came to mind was potential venting from the Chernobyl coffer. With such political chaos in the Ukraine, not likely we would hear much.
Does Sweden have a government radiological monitoring net that you could check?

Yes I probably could find out the wind direction, but so could you.

I doubt that the political chaos you mention should have any impact of information about Chernobyl. The reason is simple, there are way to many scientists and other professionals of various nationality working on a daily basis in Chernobyl.

I believe that I do not have access to those monitoring systems that the Swedish authorities has, but I may be wrong.

Thank you for your input.

Regards

Carl