There are many differences between Summer and Winter. Winter species are generally darker, browner and 'plainer' than the summer species, and of course there is much fewer adult moths active and flying during the winter
I've not noticed any changes in that respect, but I've only been doing this recording for 5 or 6 years, so not really enough time for me to notice any changes in trends.
When I talk to more experienced recorders (30 years+) they talk about the change in numbers (lots of species are in decline, just like other animals/ecosystems around the world). They also mention the seasons are changing and so the weather is happening earlier than usual. For example, our Winters are becoming milder, and our Springs seem to be starting earlier, so that certain species are appearing earlier in the year.
These changes are worrying, because the ecosystem is very finely balanced, and even small changes and affect that balance
Well, I imagine the same thing as diurnal butterflies: many populations are being affected by climate change. 6 years seems short, but it's a long time!