If your unlucky and your local extension office doesn't keep their climatalogical data online, I found a neat site that has some information.
Here is a link that might be useful: Climate Data
Thanks Justin, that's a great find. I guess I have trouble understanding the numbers, but fortunately our extension does have alot of the info that I think is valuable.
Nice compendium of the data and nice charts. I'll bookmark that. Thank you.
For those of us who like to push the envelope as far as possible, the raw data in jleiwig's link can be found here (my nearby station), and clicking around in the left margin's links will get you to your nearby station, where all the raw data are compiled and tabulated.
For example, freeze free days is useful for season-extending operations and probabilities of success (or probabilities of madly scrambling around with old blankets)...
I too have an online service through my university extension. It's called OARDC. It gives me air temp, soil temps, and anything else I really want to know. I usually query the last 10 years. Of those ten years, soil temps have been above 50 degrees on or before april 21st 7 out of 10 times I think.
Here is a link that might be useful: In depth weather data for my area