It really sounds OK, as long as you are nursing him on demand. Make sure you are drinking lots of water!
Supply is generally going to catch up to demand (unless of course there is some other factor like pg or meds). If the weather is heating up, his nursings are probably picking up, and your body is probably trying to catch up. So, there may be a little "delay" ~ nothing to get worried over.
Under the "I don't know if it helps, but it made me feel better" category.
Whenever I was worried about supply (like a temp nursing "strike" or we were apart for some reason or just a busy week with little opportunity to nurse), I would express milk while I was in the shower. The warm water seemed to help things flow and it helped me feel like I was doing *something*. I doubt it was really necessary, but I don't think it could hurt anything.
My DS started going longer between wet diapers around 1 as well. He would only pee like 3 times a day and the dipes would be SATURATED!