What season is it in Jerusalem Israel?

Right now, January, it is winter.

As Israel is in the Northern Hemisphere, the seasons are:
~21 December - ~20 March: Winter
~20 March - ~20 June: Spring
~21 June - ~22 September: Summer
~22 September - ~21 December: Autumn

The dates above are approximate, as the exact date and time of the solstices and eqiunoxes (ie. when a season changes from one to another) varies each year.