I am in zone 5, and I plant seeds the second week of June.

Sometimes is it cutting it close for the big winter squashes to get 'ripe', but the plants really suffer if you plant them before the ground warms up.

I don't fret about what the temp is when they are setting blossoms, summertime temps are so unpredictable here, the best I can do is get the plants off to a good start and keep them mulched and watered. I usually have good harvests.

I am in zone 7B and i plant my summer squash the first of may. I have a confession ; from the 14 kinds of vegetables I plant squash is the most abundant production I have. I harvest it every day because I want young and tender. The problem I had with squash is the powderly meldow which fungi spray takes care of it.

Well when I plant squash the blossoms it sets are a ratio of about 10 times as many male blossoms as female (i.e. for every 5 male blossoms I get, I'll only get one female blossom) I know that the male blossoms set and appear first, but this ratio continues to happen even after the initial set of male blossom.

I grow my squash in lg. plastic storage containers; this provides insulation for the plant with temps early in the season. However in the middle of the summer I am wondering if it's overheating the container and creating
the problems with no female blossoms?

I'd like to try and plant the squash in both the recommended planting date (28th of May) and try planting them later in the summer to see which gives a better yield and sets more female blossoms.

When should I plant them to get a fall harvest? I know that the 28th of May would be too early to accomplish this.
Even if I were to plant them in mid-june, they woud still be doing blossom set right in the middle of the summer (Aug).

I have yet to have success with planting squash which is why I'm wondering if the problem is with the planting time.

Also the soil mix I use is very coarse and heavy. I know tomatoes get blossom end rot and have problems with fruit set because of this. I'm wondering if the soil being too coarse (which causes it to dry out too fast) causes problems with fruit and blossom set due to it being inconsistently moist with squash?

I get my squash seed from Johnny's in Maine. They have a lot of vegetables for northern climates. My favorite is Confection which is a gray kabocha type and keeps very well. Generally, Memorial Day weekend is considered the time to start vegetable gardens here in NH. You can try starting sooner and protecting the bed with garden fabric (I get Agribon from Johnny's). You might also try protecting the bed with a low tunnel. Both the fabric and a low tunnel (mine is covered with fabric) also help protect plants from insects. I take the fabric off when the plants are larger.
I also like to use lasagna gardening ideas to built a garden bed. Some people call it sheet composting. Build the bed with fresh grass clippings, old leaves chopped up, straw, etc. I top it with a layer of composted horse manure. Lots of organic material in the bed will help hold moisture. Good luck.

what variety do you want to grow, there are ranges of days to maturity, estimate when you want to harvest, count back to the day you want to plant, find a variety in that has a close number of days to maturity.

so if your freeze date is estimated to be October 1st.
give estimate 45 days for fruit to mature (or 45 days of harvest time) you would need to have a maturity date of around August 15th. giving 2 weeks for germination, you'd have about 90 days to maturity once the seeds germinate.
so you then find a variety that has 90 days or less to maturity. (this all supposes that all weather events are in your favor, rain, sun, heat, soil temps, etc.) but it's a good estimation, I've been using this idea for a long time with much success.

math was a little off, I was planning on a May 1st seed date. With a June 1st seed date you'd have about 60 days to maturity not 90.

plant 6/1
germ 6/15
maturity 8/15
harvest until 9/30
blizzard hits 10/1...winter is here.

I plant my winter squash around the beginning of July and always get a crop to harvest about the end of September.