Question: Last night, I walked home from my bus stop (in Belgium). Since it was around 11 PM, it was quite cold, probably only about 4-5 °C. However, it didn't actually feel cold at all, and I didn't feel like I had to rush to get home for the cold. In fact, I didn't have headwear on, but I didn't get cold ears. It was about the same temperature as this morning, but the difference is that this morning felt a lot colder, probably due to the wind and drizzle.

I tried to describe it in English on Twitter, but I couldn't actually find a proper word to decribe it. I considered "a warm cold" or "a cozy cold", but I thought these were too poetic, more like something you'd use in a fairy tale than in a tweet to a handful of followers.

How can you describe that temperature without it becoming confusing or poetic?

Answer: 
I realize this doesn't serve the single-word tag, but perhaps you could separate the temperature from your perception:

'I was unaffected by the cold' or 'I didn't feel the cold'

With your description of the morning you could state: 'compared with the rainy wind in the morning, it didn't feel cold.'
I would say "chilly" or a "nip" in the air.