It depends. Maybe colder, maybe not. (Yeah, right.)
Anyway, two major rules for hammock happiness:
(1) Sleeping pads don't work.
(2) You must arrange your rain fly to block air flow.
Sleeping pads: Are normally 20" (51 cm) wide. The hammock will wrap around your body. Your shoulders and knees (and possibly your elbows, upper arms, hips and thighs) will contact the hammock wall at various points because of this, and though you won't lose significant heat due to this contact, it will drive you nuts and keep you awake all night. Also, a sleeping pad under you means that moisture can't escape. But just about any pad you can get ought to keep your bottom side warm for most spring-summer-fall trips.
Rain Fly: I usually sleep on a slope. I hang the up-slope part of my rain fly straight down, weighted by a trekking pole hung horizontally. (I sewed on a couple of extra tie-outs for this.) The down-slope side of the rain fly can be raised as much as I want for views. Since cold air flows down mountainsides, this arrangement defeats the draft.
Some means of blocking foot-to-head or head-to-foot breezes is necessary at times. Sleeping in still air significantly raises hammock comfort. Don't be fooled by sales photos of hammocks with their rain flies splayed out flat. That won't work unless you sleep so hot that you could just as well snooze naked in the dirt anyway.
A minor rule: Something over the top such as bug netting helps block draftiness, but that isn't enough for me. I add a piece of super-light fabric over that when needed. I once used some super-thin, super-breathable non-woven fabric that covered a scanner I bought. Don't know where to get more of it but it was great. The right weight of "interfacing" might work. Haven't tried it, but look here for some ideas: https://en.wikipedia.org/wiki/Interfacing and http://www.joann.com/fabric/utility-fabric/interfacing/
Suggestion: Try a few close-to-home nights outside before doing anything adventurous.