Was at Walmart at Gran Plaza last night, (not the tourist one off the R2 bus line); giant selection of big ol Yellow Lemons. Costco has them as well, atleast most of the time. And my ex's dad had both lemon and lime trees on his prperty. They are here, but not very common and for the most part are not used my most. I pointed them out to my current bf last night and he had no idea what they were. To me, using limes on everything here, even making things that require lemons make no big difference at all. Chances are you will only get limes no matter when you go and no matter what you ask for.