The weather makes a big difference in training, but I think it is mostly the speed that is compromised.
It is impressive that you can run any time of the day, late in the morning, at night, ... Your body is very flexible and can adjust to any schedule!!
My update: Fri evening I had a nap instead of a short training, then did some callisthenics at home while listening to the rain outside. Sat morning 25k easy w my Italian fellow runner, not satisfied by the pace. So on Sat evening I did 3km at 11km/h at 21:30. On Sun morning I was tired, so I did just 15km easy. Then I hit the spa, so in the evening I had rested enough to do 12km in 1:05hrs, incl fartlek and about 1.5km @ 13km/hr. Not exactly a speed session, but I am slowly getting there!
Total mileage for last week 161km. Hmmm...
This week's plan: today maybe take the whole day off. Tomorrow a 20-22k incl 2-3km fast finish, if the weather allows for it. In the week 12-17k sessions, evening sessions faster and shorter. Saturday a long run of 25-28km, dep. on the weather. Sunday easy 10-13km. Aiming for 140-150km mileage.
Also in my plans: in the end of January I want to take 4-5 days off from training to rest well. To give my body the chance to rest before the final prep. for Rome.
My training plans for Rome- My worries: cobble stone. And the potentially hot weather!