Whats the best week to bow hunt unit 9 NM?

Generally the last week or two is the best as if the weather is cool enough the rut will be starting. However two years ago when I drew a tag in Unit 10 (just south and west of 9) the morning temps were in the 40-50 range and daytime highs were up to 75 or so. The rut didn't really start until ML season that year.