I would say that trying to make a prediction of the weather in any month of the year in this area is like many other areas of Europe and for that the World....Impossible to say what it is going to do these days.....Snow in Texas last weekend and Saudi on Tuesday, camels in the desert laying on the snow.....I was in Spain and Portugal over Xmas and the New Year and the rain was fierce for two weeks apparently and the day after we got to Portugal it stopped and came out sunny for 3 weeks, with frost at night, when we returned through Spain last week, there was freezing fog in the valleys and the tops of the Extremadura mountains were 12 - 15 degrees and bright sunshine, all very weird!
I would be more concerned with the cinereous Vultures and how you would fare if unable to move or knocked out if you come off your bike, as the vultures are the largest in the world with a 10ft wingspan and weighing up to 20K and they do have the largest beak of any bird in the world and we encountered a group of them and they are fucking huge....Properly tooled up for ripping you apart, they feed on boar, cows and sheep.