Unless your house is airtight and the air in it thoroughly filtered, and you have a decontamination chamber for your front door, you're already
getting pretty much the same amount of radiation from Fukushima as you would outdoors.
The amount of radiation in rainfall, though many times higher than the ambient radiation released from Fukushima, is also not much to really worry
about if you're an adult in North America or Europe, particularly if you do not ingest it.
I explained a bit of that regarding the video posted
in this thread. Depending on which
part of Canada you're in, odds are the amount of radiation in the precipitation where you are is at similar levels as that, or lower by now, given
the amount of time that had elapsed between the major releases of radiation at Fukushima and the date of that post, and the time that has elapsed
since that post and today.
For more information about radiation, what constitutes a life-threatening level of radiation, and other information, I will shamelessly direct you
towards my thread on the subject,
here, which I updated with what I've subsequently
learned about counts per minute.