Storing data on a regular lat/lon grid

Hi all,

I have temperature data that has been interpolated to a regular lat/lon
grid. I have one grid per day.

I want to be able to select points within a certain region, and within a
certain time period.

Now, I could store each grid point as a separate record (a new row for every
single point/time, with columns lat, lon, time, temperature), but since my
grid is constant, there's a lot of redundancy there, no? Disk space is
somewhat of a constraint, since there are a lot of files.

Basically, has anyone done any work with storing gridded spatial data? I see
lot's of info on Geospatial data, but it's usually cities, stations, etc.,
not a regular grid that doesn't change...

I also noticed that PostGIS does not support raster data...

Thanks a lot,

--
Mike