I meant 'pleasant' in that the walk itself was enjoyable. Even though the temperature was rather low, the bright sun and clear sky made it feel warmer. That, and I hadn't done a major walk in over a month (and normally I'm an avid walker), so the chance for some exercise was refreshing.
I do notice I said "only" -13°C, which granted is already pretty cold. But compared to, say, -25 or so, -13 is relatively mild.