rhe egg cycle has little to do with the temperature, it is to do with daylight hours. it could be minus 10 but if the hens are getting food and water and are health AND have extended periods of sunlight, they will lay. its about how long the bird is "awake" for to make the egg
Yes; the days have been a lot lighter this winter, very little cloud cover, and if it wasn't for the cold, it would be like spring days, blue skys, sun !!
Cheers.