Hi Matthew,
I am similarly trying to interpolate weather data over time. While I am still working out the finer points, I have found that you can use the 'model builder' tool, with an 'iterate features' iterator. Plug in your dataset as the input for the iterator, and then set it to select features by your date column. Then, still in model builder, use the interpolation tool (if you're doing weather, probably a Kriging interpolation is best) with the iterated output as the input to the interpolation. Run the model, and it should quickly (well, relatively quickly) produce your interpolations.
Also, you'll want to use %n% or possibly %value% at the end of your file name for interpolation output, otherwise model builder will just save over your previous files in each iteration.
Let me know if this works for you.
Best,
Dan V.
ArcInfo 10sp5 with extensions
Dept. of Political Science
Wayne State University
Detroit, MI
