Six month limit for northerners?

Sort of accurate, we can stay 6 months and must return to Canada for 24 hours before may return to the USA.

Or what?

My understanding is if you spend more than 183 days in the USA in a 12 month period , the IRS wants you to pay taxes on ALL of your income.
So you would pay Canadian taxes and US taxes.
Note that it is 183 days so they don't have to be consecutive.
Hopefully someone with more experience will chime in.

I think you can go into Mexico for a day too. At least that's how it worked between Thailand and Vietnam, just gotta get that stamp on your passport or visa. But with Canadians not needing either I don't know how it's even tracked. Same with Italy and France, but that was pre- EU days.

US immigration only allows Canadians to stay up to 182 days in a 12 month period, be very careful and keep track of the days you spend in the USA. Every time that you enter the USA even for a few minutes counts as 1 day

USA IRS considers you a usa CITIZEN FOR INCOME TAX PURPOSES IF YOU SPEND MORE THAN 180 DAYS IN A 3 YEAR PERIOD ACCORDING TO THIS FORMULA days of current year + 1/3 days of previous year+ 1/6 days of the 2nd previous year. to avoid paying USA income tax complete form 8840

Visit Cdn snowbird association web site for details and explanations.

We normally leave Canada around Nov 5th and return around April 15th

Make sure that you understand the rules and you will not have any problems

Yeti plus is sort of right (the yearly limit can fluctuate depending on leap year...usually 180-181 days). DHDW is very correct and the other point to remember is that each province has a minimum that you must be in your province to retain health services. Going to the USA for 6 months and then another Canadian province for 2 months could be a problem. As DHDW said, make sure you know the rules. Asking on a forum is helpful but you can't always rely on everything in a forum.

Plus...

Your health insurance is Provincial so you can't be out of Province for more than 6-7 months depending where you live.

You can't spend 6 months in the States and spend time in some other province other than your home and still be covered..

DHDW & Netjam are most accurate here, but of course one should check with the governing resources on anything so important. If you spend more than 120 days per year averaged over a 3 year period in the USA I believe that is the correct timeframes, you should complete a "closer connection" form, and when crossing the border have this to hand as well as proof of "closer ties" to Canada ie; deeds of property, drivers licenses, utility bills, bank statements etc. Generally to prove to the admitting officer you can support yourself whilst in the USA for almost 6 months = not illegally working; that you have a reason to return to Canada.

Each province also has different rules on amount of time one needs to be in province to retain health care privileges. There are exceptions to this upon application for once or twice in a lifetime exceptions. We are unclear if there no paper trail (ie; Cash not credit cards used) how they can prove length of time in the actual province of residence, but we are aware that information is now readily being exchanged between the USA and Canada on entries/exit dates etc. We are also aware of others in the past having overstayed their welcome and being banned from entering the USA for up to 10+ years after the fact. Just as we met Irish folks for 9+ years illegally living and working in Santa Monica, until they finally got green cards under some kind of lottery system. Amazes us how their children were schooled etc. Guess there's a way around everything if you know the "underground" systems.

Bottom line is BIG BROTHER is watching you, so best to know the rules from officialdom and adhere to them. If more time required or otherwise apply for the relevant visa/permits.

Here's a link from the Canadian Snowbirds Association. Lots of information on their site...
link

DHDW&2dogs wrote:
US immigration only allows Canadians to stay up to 182 days in a 12 month period, be very careful and keep track of the days you spend in the USA. Every time that you enter the USA even for a few minutes counts as 1 day

USA IRS considers you a usa CITIZEN FOR INCOME TAX PURPOSES IF YOU SPEND MORE THAN 180 DAYS IN A 3 YEAR PERIOD ACCORDING TO THIS FORMULA days of current year + 1/3 days of previous year+ 1/6 days of the 2nd previous year. to avoid paying USA income tax complete form 8840

Make sure that you understand the rules and you will not have any problems

This pretty much sums it up. Both sides of the border are now able to share data electronically so folks really need to play by the rules.