Here in the pacific northwet, I would say I wipe my chain down 1/week in the rainy season, and give it a quick spritz with the lube of choice after. I will grab the brush and cleaner and clean the rear cogs and derailleur about 1/month. I give the whole bike a quick wipe down with a rag about once a month as well. It gives me a good opportunity to look for any issues like the beginnings of cracks or rust spots.
During longer dry spells, I check the whole thing about 1/month, and don't usually need to do anything else to keep it going. (I ride a recumbent, too, so my chain is about 3x longer than most bike chains.)