I have read on here that for some people the need for insulin is reduced in the heat of summer. I have been having to up my insulin to carb ratio from 1-20 to 1-30 over the last few weeks and then the last 2 days I have only used it twice. Yesterday at lunch 1-35 ratio and was at 89 2 hours later. and at supper tonight tried a 1-40 and am at 99 at 2 hours after. Don't get me wrong these are wonderful numbers but I'm feeling really paranoid( waiting for the other shoe to drop). Can you get a "honeymoon" 1 1/2 years after starting insulin?
Heat does tend to make some people less insulin resistent, but I too lately have had to up my basal rates and for no really good reason, other than just because. My best advice monitor a lot, and when you start seeing trends like numbers getting lower, then decrease a bit.
I think a few things happen in the summer. First, you're moving around more that increased activity reduces your need for insulin and any insulin resistance you might have. In addition, the heat makes insulin absorb faster and more effectively, and this too can decrease your need for it (because less of it is "lost" through bad absorption). Finally, the insulin fairies come around more frequently in the summer and shower you with insulin in your sleep. Ok, I might not have that last one right, but that's what I like to think :-)
I like the insulin fairy theory!