So what's the coldest outdoor temp that you can go in a hot tub?

[rick_in_cleveland]

A number of years ago, while in Steamboat Springs we went in at minus 42.   There was a temperature inversion and all the cpold air settled at the base.  There was no wind and when we walked back to the room all you saw was a moving cloud.

[rin-spa-aic]

To you guys who run your tubs in -30F or so weather, are you getting massive electric bills?

Obviously our electric bills go up. It becomes even more important to have a well insulated tub. 100 bucks for the month for a middle of the road tub. 50-60 for a well insulated tub. Heard stories of, not to mention any manufacturer names................... but Master Spas, Coleman/Maxx running 120-150 per month in severe cold. The size of the tub makes a huge difference. The wind, how much you use it are all factors.

Not sure what size tub it takes to get to $120-$150/month my Maax operates more in the middle of the road numbers you provided $50-60 in winter with 4 hour filtration + freeze protection and used multiple times weekly. Doubtful it would ever get to or over $100.

[Terry Action]

You guys are lucky not to live in NYC. Mine has to be closed for the Winter because it's so much.

[Dr. Spa™ Ret.]

It's not as much the size of the spa, as it is the build and insulation quality.

[Spoiledrotten]

We were in ours at 12*F this week. Loved it! That's the coolest it's been for us in years. So much steam that you couldn't see the opposite corner of the spa.

[Tman122]

It's down right balmy here in Minnesota today at 13 degrees.