The menstrual cycle certainly plays a part in the variability of symptoms, and what you describe is what I have experienced, so much so that I get one day out of the cycle where I feel completely normal often.

I feel better in colder weather, and my neurologist told me that all humans had better neuromusclular functioning in cooler temps. That said, I do get Raynaud's, which involves circulation, which renders my hands and sometimes mouth quite useless.

For me, too, my symptoms get worse right before my period.

The clinical description of MG (as written some places, at least) says that symptoms are exacerbated by extreme temperatures. I know that most people feel weaker in warm temps, and i do too, but the cold also affects me in a way that sounds similar to you, when my hands and feel get the slightest bit cold they become numb and are difficult to move. In fact, one of my first indications that something was wrong, before I was having symptoms every day, was that I couldn't move my lips after eating ice cream.

I suffered really bad with my fatigue during the cold icy weather here in England back in January, compared to just the normal cold weather we get. My legs just wouldn't work at all for longer than 5 minutes when out in the cold, they went stiff and were just completely useless. However, at the time I was not on any medication, but noticed a huge difference and found it easier to walk indoors, where it was slightly warmer. My hands and fingers really do not like the cold either, makes them feel numb for quite a while. I hear that MG symptoms are known to develop when the weather increases, I'm yet to experience this, and doubt I will to a certain extent as it probably will only reach 20degrees for about 3days over summer here haha.
With regard to the menstrual cycle, I use to feel weak for the first day. But I control it with the contraceptive pill now and have been for 5months which has really helped me and doesn't make me as weak when due. And I've had no problems with it since starting on my MG medication 3 weeks ago, was worried at first in case it would have a bad effect towards my medication, but it doesn't and has been confirmed by my specialist to carry it on.

I feel the weather changes here on the Gulf Coast. It doesn't matter if it gets warmer or colder-any large dip in temperture makes MG flare. It is very humid here too.

Both the cold and hot weather decreases my strength. The cold is the worse. As you can see we are all different. God bless. Cabbage7

Cold weather is far better for me than the heat. In hot weather my MG is extreme whereas in cold it is much more functional. Seems to be different for everyone this dratted MG!

Yes have to agree, th hot weather is worse for me. I am not looking forward to the hot Texas summer.
Annette

I agree with vieve, I have noticed for a number of years my lips become Frozen and can't be used when I eat ice cream... Or my hands when they get cold get REALLY cold and I can't use them either. My feet my dad hates I'll sit on the bathroom sink counter and run my feet under hot water because they are freezing and purple. Or in the summer my feet people ask if they are okay because they are beat red in the sun. I never thought anything of it. Then recently I thought maybe I had Raynolds disease. I never associated it with mg!

I totally agree with Potato11. Cold is terrible for me. I get so slow and weak. Humidity just makes me weak. I usually layer my clothes to a ridiculous degree. My family is considering moving... Not sure where we would go? I think I need to get better meds first.

ShanAllis, it does sound like you have Raynauds. Lots of warm gloves and socks for you. And maybe meds for it. Have you discussed that with your doctor? I do the warm water thing, too.

Thyroid hormone does affect cold and heat intolerance, as do a lot of generalized autoimmune disorders...so a lot of us will be affected one way or another...and of course adding steroid to the mix complicates this... I find it weird that a side effect of Mestinon is sweating for those of us who have cold intolerance:)

I am weaker in extreme cold weather and also extreme hot weather! I was living in Texas when I was first diagnose with MG in 2011. I have now moved back home to Michigan.