it depends on what you are looking for.
Jan and feb usually have the best sending conditions of the year, but also more wet (unclimbable) days.
Some areas and problems might be wet or in sub-optional conditions throughout this whole period due to morning fog and humidity staying trapped in the bottom of the valleys.
This time is your best bet for projecting problems at your limit and located near the top of the hills (for instance, if your limit is around 7c-8a, this is the time to get on the big five @rempart)
March and especially april usually have a more mixed weather and more wind.
You will have quite a lot of suboptimal yet still climbable days with short rain spells that could dry out relatively quickly.
You might have better chances on shady, less elevated problems/areas.
Yet condensation might be even more of an issue on non-windy days, due to the higher temperature difference between night and day.
Overall it is a better choice if you want more climbable days; yet finding perfect sending conditions will be bit more tricky- good knowledge of the various areas' micro-climates and luck will make the difference.
