Check the definition of icing conditions for your company and aircraft. For us it's less than +10deg C, in visible moisture (ie rain, cloud, or visibilty less than 1km). After the temp drops to less than -40deg C, its no longer deemed icing conditions.
If you're going to encounter any of this in flight, then it's a no brainer. Don't go.
Had exactly this discussion with an engineering manager who had been dragged out of the hangar to rectify the fault. Just because it was nice and warm and sunny at base he wanted me to take it. I had to tell him no 3 times
