With warmer weather finally getting here, it is just natural that your body requires more fluids. If you are challenged with remembering to drink fluids while riding, keep an eye on your watch/timer and take 2-3 swallows on regular intervals-like every 10 or 15 mins. Also, you probably want to consider something other than just water for the longer rides and warmer days.
I felt puny yesterday pm after two longish rides Saturday and Sunday and I'm sure it's related to not hydrating properly!!