What happened to the nice warm weather?
Yesterday I was in 3/4 tights and a YACF jersey, this morning I needed full length tights again, a fleece over the jersey and gloves with my mitts. It was over 10°C cooler ... 13-14°C yesterday, and 3°C today ! (and last week, it was even warmer).
Having said that, it was dry, and sunny for the second half of my ride. Cooler weather is easier to deal with than wet weather. This time of year is always a bit more unpredictable than the rest of the year.