That's really interesting. Canada is a very large country, I live on the southwest corner of Canada. The winters here can fluctuate from +15*C down to -20*C from one or two days to the next, seriously! And the dry wind can really play havock on the RH level in the shop. The other day, I thought I put the water container back on my humidifier correctly, the next day I went into the shop to check on it and check the RH level. Well, my hygrometers told me that the RH had dropped 10% over night!

What the heck happened? I checked my humidifier, it was still full! I did not seat it right on the base and no water was introduced into my shop. I fixed that and today, the RH is back up to 43%, right were I need it.
There is no way to tell really where the humidity level is going to go and I certainly wouldn't trust environment Canada to tell me when it will be reasonable to go ahead and glue up my guitars. Being able to control the environment is really important if one wants to do more than make moderate quality guitars or guitars which will be sold (even at discount) to others.
I certainly hope that other builder (who doesn't have RH control, living in Canada) has a good or several good hygrometers in order to tell what the RH level in his shop is. Again, depending on where he lives in Canada, the RH change from Winter to Summer can be from 20%-80%. That's not something to leave to chance as far as I'm concerned.
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