New station in central Israel 4x6gp

Hello,
My name is Victor, and I have just activated my Radmon+ station with SBM-20 tube in Rehovot, Israel. The name of the station is 4x6gp (my ham radio callsign).
I initially located the Geiger tube outside of the window of my apartment on the top floor of a 10-floor building. Counts were running around 40 CPM, which seemed a little high, but last night we had significant rain and the count went much higher. The Geiger tube was in a plastic tube just a bit larger than the Geiger tube, and I think the rain contained either radon decay products or radioactive dust particles, which stuck to the plastic right next to the Geiger tube.
I have another SBM-20 counter which sits on my workbench and did not notice any increase.
I moved the tube indoors near an outside wall of concrete blocks and the counts seem more reasonable.
This whole subject is very interesting and I might try to develop an outdoor mounting that will keep the rain farther from the tube. On the other hand, perhaps the indoor readings are equally informative, since the variations are more important than the absolute values.

Welcome Victor. My name is Steve, callsigns G8CYE and CT7AOX. Location is in Portugal.