Originally Posted by jpalarchio
I've used the Maxim One-Wire sensors for this.
With a little programming, you can put together graphs like this: http://temps.palarchio.com/
Wireless is going to be expensive, you're either going to need a small PC or Arduino down in the basement or run at least one cable down there to connect up to the sensors.
+1 for 1-wire. I use the 1-wire for various items in my house (Outside, inside, freezer, keg fridge, lager box, etc). You can run them all in series on a single pair of wires (bell wire or cat 5).
I use the Digitemp
software to read the temps. You can then use the rrd tools to make the graph. IIRC, there was a detailed webage on the Digitemp website on how to do that.