Thought some of you would be interested. There is a little unix worked in here... I have a lot of temperature data in a giant file. I think I got it by grabbing a bunch of different files on the web and putting them together. They are from a legitimate source. In case you want to see the file, it is here: http://taxa.epi.umn.edu/~mbmiller/temperature/all_temps.txt That tells me all the temperature highs and lows for every day for the 99 years from January 1, 1900 to December 31, 1998. Using that file and some neat computer tricks, I put together the table below about last frosts for every spring for all 99 years. The earliest final frost was on April 7, but that only happened once. In 25% of years, the last frost was on April 22 or earlier. In 50% of years the last frost was on April 28 or earlier. It's really only safe to plant after May 24, but it's 90% safe after May 15. I'd say that if our weather forecast predicts no cold weather for a few days, you can be safe even a little earlier. On Sunday afternoon our 103-year-old neighbor told us there would be no more frost this year. He also called me "Tom" so I have to wonder if he was thinking clearly. I'd say that we have about a 90% chance of at least one more frost before summer. Mike tail +12 all_temps.txt | head -36159 | gawk '$2 < 8 && $5 < 33 {print $0}' > junk # in tcsh shell: foreach year ( `seq 1900 1998` ) grep ^$year junk | tail -1 >>! junk_2 end gawk '{print $2" "$3}' junk_2 | numalign | sort -n | uniq -c | perl -pe 's/^ (.) (.) (..)$/ $1 $2\/$3/' > ! output.txt numalign is here: http://taxa.epi.umn.edu/misc Last Spring Frosts for Years 1900-1998 ======================================== Frequency Date Chance of No More Frost --------- ---- ----------------------- 1 4/ 7 1 4/ 8 2 4/ 9 1 4/10 5% 1 4/11 1 4/12 1 4/13 1 4/14 2 4/15 10% 1 4/19 3 4/20 4 4/21 6 4/22 25% 4 4/23 5 4/24 2 4/25 5 4/26 6 4/27 3 4/28 50% 1 4/29 3 4/30 4 5/ 1 4 5/ 2 5 5/ 3 67% 1 5/ 5 3 5/ 6 3 5/ 7 1 5/ 8 75% 2 5/ 9 3 5/10 4 5/12 4 5/13 3 5/15 90% 1 5/16 2 5/17 1 5/18 95% 1 5/20 1 5/22 1 5/23 1 5/24 99%