Why would Jesus look for figs out of season?
The simplest answer is that Yeshua was looking for figs out of season because the tree was promising them.
Too often we focus on the lack of figs and the cursing of the tree, but fail to take a closer look at in the big picture.
And seeing a fig tree afar off having leaves, he came, if haply he
might find any thing thereon: and when he came to it, he found nothing
but leaves; for the time of figs was not yet. —Mark 11:13 (AV)
The time of year was Passover (cf. 14:1), the middle of the month of Nisan (April). In Palestine the fig trees produced small edible buds in March. This is followed by the appearance of larger green leaves in early April. The early green “fruit” (buds) were common food for local peasants.
In the passage under consideration, the absence of these buds, despite the tree’s green foliage promising their presence, indicated it would bear no fruit that year. Eventually these buds dropped off when the normal crop of figs formed and ripened in late May and June, the fig season.
Thus it was reasonable for Jesus shortly before Passover (mid-April) to expect to find something edible on that fig tree even though it was not the season for figs.
In summary, the tree was making a promise of fruit (because the tree had leaves). Here in my own back yard, I have a fig tree that produces leaves and fruit at the exact same time. When the leaves first appear, the fruit comes on at the same time. Thus, if there are leaves, there is fruit as well. Since the tree in Mark produced nothing that was edible, but had promised to do so, it was cursed by the Savior.