I always used to just plant things out when it was warm, but I've had a 4-year hiatus from proper gardening as mumming took over! But this year I thought I'd do it properly! But if putting them out on a warm day is good enough for you, I'll do that.
But not this week. Metcheck are forecasting several nights below 5C, so I'll wait! I just potted everything up, so they should be ok for a bit longer!