Average high and low temps and record lows. It is close to the bottom of the page. Otherwise you have to go to NOAA and try to find something there. That will take you days to find.
IFR,
There are maps of low one-day mean ambient temperature in API-650, AWWA D100 and NFPA-22. I believe that all are based upon data directly from the national weather services of the USA and Canada.
I use the maps but I was looking for an better way than looking on a road map for a particular location and then guessing at the location on the API or AWWA or NFPA maps and interpolating between squiggly lines. The seismic applet works pretty well - I was hoping for a labor savings tool for temperatures as well.