I think since it’s a little too warm, maybe set up a shade cloth over your plants. At least to get them started. There are some lettuce plants that are bred more for the heat (Johnnys seed) sell them but sometimes I cover them up with shade cloth when it’s extremely hot in the summer.
First time growing winter vegetables; not counting last years lettuce. I’ve sowed carrots (old seed) as an experiment and parsnips. If the carrots don’t germinate, I’ll plant the newer seed.