Here, our 10 day forecast has highs as warm as 67° on Saturday, and as low as 32° on Thursday. It happens to a lot of us, Xeramtheum. And as Joanne points out, days are still short. Limited light.
If you keep containers in shade, and avoid sowing tender things until spring, it helps. I haven't had really early, problematic sprouts since my first year, 8 years ago. Then, I had sown some quick sprouting annual seeds. Now, I don't, until spring.
And I haven't started sowing yet this year. I've learned a few things in 8 years!