Insulin and cold weather

I live in San Francisco where the weather is generally mild, in the 50's - 70's. About a week ago, the weather dropped 20+ degrees and has been steadily cold in the 30's and 40's. All of a sudden, out of nowhere, I was getting lower and lower at the end of Day 1 of the cold front. Over the next day or so, I need FAR LESS insulin than usual. I have been using an insulin pump for just over 3 years and have NEVER had this experience before. As of the weekend, I am now dosing 40% less basal and 50% less bolus.

As I said, this has never happened to me before. I've been in the snow and freezing temperature for 5 days and this didn't happen. I do sometimes need more insulin in the heat and when traveling, but not a 40-50% difference than my regular dosing requirements (maybe a 15-20% change).

I have not had any changes in insulin and take no other medications. No diet changes. Nothing different at all. If anything, I ate a little more because of Thanksgiving and snacked maybe a bit too much.

Has anyone else experiences THIS MUCH OF A DIFFERENCE before? I mean, it seems absolutely crazy to me. 50% less in my bolus?!?! It's just wild. I cannot wrap my head around it.

Interesting, Amanda. I'm north of you in the mountains of northern california where it's significantly colder than the Bay Area. So it started getting quite cold, especially at night several weeks ago and I have been having repeated lows and having to lower and lower my insulin. I too have not had this experience. Actually the only temperature related experience I had was when I was on a trip to a hot and humid place and needed significantly less insulin. Less for both hot and cold?? Doesn't make much sense. But I guess I'm finally learning to just "go with it" and adjust insulin by need without wondering why. Still it's strange. Maybe California put something in the water (kidding).

i know, right?! this is just so weird to be happening. and, that you too are having this experience. it's just so strange to be so drastic, is all.
i just adjusted my settings the last 2 nights because the same was happening to me. i usually basal at around 1 unit per hour (depending on my days activity) at night. i'm now on .4 units per hour at night with absolutely no changes to my bg levels. that's actually a 60% decrease in insulin at night.
but, yes, true. you kind of just have to roll with whatever happens. no rhyme or reason to type 1.
thanks for your response. it's sort of comforting that it's not just me. ;)

Mine isn't that much. My basal in October was 12.80 and now it's down to 11.30, so that's only 12%, but still seems like a lot and the last couple days I've been having more lows so may have to adjust more (and the last couple days our temps have gone even lower). Yep, Type 1 is always entertaining!
Btw do you know about the Type 1 Women's Group in the East Bay? I started it three years ago and it's a great group of women!

i do not know about that, thanks for the info! will look at it ...

I'm talking about a live group. If interested send me a message and I'll give you the contact person.