Ive been taking methimazole for my hyperthyroidism for ten years. during this time my temperature was low, sometimes 96.5. im improving & down to one pill a week now & noticed my temp is around 98.5. would this be related to the decrease in meds?

It is possible. If your temp was low because of medication induced sub-clinical hypothyroidism so when the dose is tapered, your temp is higher although both numbers are still in normal range. The best answer will be a new thyroid function test with TSH and free T4 +/- free T3 if applicable (for patients with the diagnosis of T3 thyrotoxicosis).