Everyone is different, and reacts differently to drugs. What triggers anxiety (and how we deal with dependencies) can generally speaking be tied to seasonal change, since you seem to have noticed a change in your mental health during the transaction from Spring > Summer I guess that could be a viable reason.

There could also be a number of other possible reasons, like maybe you went through some particularly tough challenges during that same timeframe, which had a stressful impact on you. Stress, in case you didn't know, is a very common form of anxiety.

Personally I experience a severe increase of anxiety during Autumn/Winter, my medical experience is a bit different from yours because during the time when I was using alprazolam to treat panic attacks, I didn't have it prescribed. I did keep a daily medical journal/diary where I included the week's dosage/mental health, mainly to keep track of my dosage. During the increased anxiety periods I kept the dosage steady and simply 'head-butted it' because it was still manageable thanks to the alprazolam. I was still obviously a mess and it was horrible, but it was doable. I reminded myself that adding withdrawals from bensodiazepines to the list of things that are ruining my life won't help me in any way.

Again, nobody can realistically answer your question (because of the previous reasons), but a good rule of thumb that helped me to keep my dosage intact without experiencing withdrawals is to always keep your bensodiazepine dosage as low as mentally possible. It is a drug that is designed to keep your head above water, not to keep your whole body afloat.

I hope that helps in some way.