On another forum advice was given that 25C is the optimum temp for cucurbit germination.
Given that this year I have had 100% germination
, I give my method, which was arrived at by trial and error over quite a few years.
Sow into tray of multipurpose compost, pushing seed in between index finger & thumb.
Wipe hand across top of tray to fill hole above seed.
Water generously and allow to drain.
Place in heated (on or off) Ward single tray electric propagator.
Put the lid on the propagator with the vents just ajar and walk away.
About three of four days later take the germinated tray out and place in an unheated propagator, gradually harden off until planting out.