Buy the 2015 Old Farmer's Almanac!
Reporting
Evan, I'd recommend someEvan, I'd recommend some filtered sunlight in the afternoon, or switch to a heat resistant variety. If you do pole crops, put your trellising just west of your spinach. Same with beets. I'm OK here in zone 6b. (Mature) spinach actually likes frost. Hope this helps.

2015 Special Edition Garden GuideCooking Fresh with The Old Farmer's AlmanacThe Almanac Monthly Digital MagazineWhat the heck is a Garden Hod?