I don't know what diet you are on, but examine it for hidden additives. Sounds like you already gave up sugars. Also beware of anything with the word "malt" in it. Could be maltodextrin, malted barley flower, maltitol., etc. That'd feed the yeast like crazy- gives me the worst gas ever! Some supplements have maltodextrin in them. If you are using Splenda to substitute for sugar, be aware that you are having more maltodextrin than sucralose, unless you are buying the liquid form in Canada (I've been told ? ).
It's hard to imagine how a change in climate could produce this problem. I'd keep looking for the answer. If need be, starting with a fast, then "testing" individual foods. Good luck.