Ive noticed my tap water PH drop on rainy/cool days as compared to hot days.

On a cool day the tap will give me around 8.1 or 8.2. Then on hot days (95% of the time) my ph comes out at a brutal 8.8 - 9.0. Crazy PH...

No idea why but I have some guesses.
GetThisOrDie Reviewed by GetThisOrDie on . Suspected, now fact I have had problems in the rainy season with all of a sudden the garden looking like hell. I use RO water because of high Iron content, but even with the RO, I got times that were just terrible. I was starting to notice this always occurred during the rainy cold season. Well, we have had 21 days straight with measurable precipitation (Wierd season). For the last 6 months I have been monitoring my PH as the RO leaves me without Cal and Mag, which I add. The Cal/Mag always lowers the PH, Rating: 5