I would and I have (400k specifically).
Starting a ride in the rain is a bit grim, I admit (as opposed to rain starting after you're well on your way). If it were me, I would break out the rain bike, bring every bit of warm and waterproof clothing I have and go for it.
Your lights should be fine in the rain - what do you have? Remember that cars may not see you as easily, so I'd add an extra rear red light or two to your bike, and perhaps an additional small white LED or two up from - for being seen as opposed to seeing.