6-8 weeks before last frost

How do I find out the last frost date for my area (Windham, CT)

I began searching the web for local information and it's surprisingly hard to find this. I turned up something at a couple of sites, see below:

Last frost dates, selected cities
Garden Web

Number after the state is days of growing season

Selected city	Days	Last frost	First frost
Hartford, CT	167	Apr. 25	Oct. 10
Worcester, MA	172	Apr. 27	Oct. 17
Albany, NY	144	May 7	Sept. 29
Syracuse, NY	170	Apr. 28	Oct. 16
Newark, NJ	219	Apr. 4	Nov. 10

First/Last frost, by zone, according to P Allen Smith (TV landscaper)
Avg. last frost

USDA Zone	Avg. first frost
Zone 4	1 May / 30 May	1 Sep / 30 Sep
Zone 5	30 Mar / 30 Apr	30 Sep / 30 Oct
Zone 6	30 Mar / 30 Apr	30 Sep / 30 Oct