Last Frost Dates (Albany, NY)

I have been researching last frost dates in my area and am having such a hard time finding a definitive answer. Do you guys have a good guide of such things? I know about micro climates and I know about my local cooperative extension (which is fairly useless in my garden's area--they didn't know the difference between hay and straw) but I want a general guide to my zone and my town for a guideline of when to start my seeds indoors. I have consulted several resources and I am either told to ask my gardening neighbors (I have none--the house is away from others and it belongs to my mother in law and I am only there on weekends in the growing seasons), to contact the extension, or the dates are wildly disparate. One source told me that Albany, New York (the largest closest city--over one hour north) had a last frost date of April 27, while another source claimed that Albany's date was June 5! How can there be such differences of opinion? So.....I ask you, do you know the average last frost date for Rhinebeck, New York? or Albany, New York. Rhinebeck is in Northern Dutchess County and is the beginning of zone 5, with zone 6 just to the south of me in Poughkeepsie, New York, the county seat and one half hour south of my garden. HELP!!!! I am so confused, starting from seed for the first time and lost about how to count backwards from a date that is more than a month in question!!!!!

Unfortunately there is a lot of confusion regarding zone maps and last frost date maps. There is some connection between them of course, but they are certainly not the same. Zone maps define the minimum winter temperatures reached in an area, while last frost date maps give the date when frost free weather can be expected to arrive in an area. These variables are influenced by different factors and the maps are therefore not congruent.
Looking at a map showing the last frost dates of the USA, I noticed that in your area the lines defining the limits of areas with the same last frost date come very close together near Albany and also do some steep southward plunges. This may explain the differing opinions for the last frost dates in your area. The map I consulted showed Albany right on the April 30 last frost date line.