Published on Organic Gardening (http://www.organicgardening.com)
Sow squash seed 5 to 6 weeks before the last spring frost. Seeds sprout in 3 to 10 days at 70° to 95°F. Grow seedlings at 60° to 75°F.
Links:
[1] http://www.organicgardening.com/seed-starting-squash
[2] http://www.organicgardening.com/learn-and-grow/squash-growing-guide