I have the same Geiger counter. I think it's a good idea to measure and RECORD baseline readings of what the radiation levels are now, BEFORE we suspect any radiation is arriving. I have checked some of the local beaches, and the levels were a little higher than I expected. But since I have never checked before, I have no idea whether that's normal.

When I do a measurement, I do a 10-minute timed sample. I write down what it is I'm measuring and where, the date, the timespan, other notes, and blocking material. Usually on the beach I have it in a plastic bag so I don't mess up the Geiger tube.

In my kitchen, I get about 0.11 uSv/h (37 CPM). On the beaches, I get about 0.20uSv/h (67CPM). At the infamous beach near Pacifica, I got 1.1 uSv/h (~370CPM).

I have also determined that at the background level in my kitchen, 0.11uSv/h, each 10-minute timed measurement has a 95% probability of being within 10% of the actual value. I also found that in order to increase the accuracy to 1%, I would have to run the sample for 100X as long (not the 10X you might intuitively expect). So, getting accurate measurements can be very time consuming.

Likewise, if the radiation level is 100X as high, I would get that 1% accuracy in a 10-minute time period. (Of course this is relative accuracy, using my Geiger counter only.)

We also have to remember that the longer we take a timed test there is more time to receive changes in the current background radiation levels that might swing wildly at times which then alter our test even more.

I've been noticing that it seems to be the higher altitude cities that have higher readings, aside from the beaches in mid and southern California. Luck of the air currents, I think.

I'm in southern Oregon in between the coastal range of mountains and the southern Cascades range; essentially in a giant valley. Our values (Grants Pass and Ashland areas) seem very low compared to the eye popping numbers being seen in San Diego.

This may be slightly off topic, but I've been wondering why the San Diego readings are intermittent? Sometimes the numbers are there, sometimes they are simply not listed.

Is that particular counter not reliable, is it an EPA site that doesn't want the higher numbers posted or what? The levels have been eye-popping for weeks now and it's disconcerting to have them go missing.

Thanks for the info and a very much needed service!

Just occasional US sub visitors to CFB Esquimalt. Oops, not supposed to mention that.

Have you done any testing along the beaches of White Rock?

The EPA station data is uploaded as soon as the EPA makes it available to the public. There can be and often are sometimes 6 hour periods or longer with no data from the EPA. This is why we need more private sites setup. In an emergency we do not expect the EPA sites to be available.

So the San Diego reporting station is an EPA station; thank you. My elderly aunt lives down there and she's been telling me that since the reports are intermittent, they're not valid.

If the station ID starts with 4: or 5: it is EPA.

I'm in Los Angeles. Just got a cpm count of ~95 at a local beach. Suggestions?

What model geiger counter and were the readings at ground level or waist?