Minecraft – How large a hole will rain fill with source blocks

The code that determines the rate of growth is:

getGrowthRate(crop)
{
    if (crop.getBlockBelow().isHydrated())
        growthRate = 4.0;
    else
        growthRate = 2.0;

    for (farmland in crop.getFarmlandIn8BlocksBelow()) //Immediately surrounding Farmland with crops
    {
        if (farmland.isHydrated())
            growthRate = growthRate + 0.75
        else
            growthRate = growthRate + 0.25
    }

    if (crop.hasNeighborCropOnNS() and crop.hasNeighborCropOnEW()) //If (north OR south) AND (east OR west) have crops
        growthRate = growthRate / 2;
    else if (crop.hasNeighborCropDiagonally()) //If any immediately diagonal square has a crop
        growthRate = growthRate / 2;

    return growthRate;
}

isHydrated() returns whether a farmland block is moistened or not. Rain does not make farmland moist any quicker than normal.

So the answer is no, rain does not affect the rate of growth of crops.

There are a few ways out if you just happen to have the right items still left in your pared-down inventory:

• A sand or gravel block: You can jump up and place blocks around and above the hole so that one of these blocks falls through you into the bottom of the hole. You can then jump up onto it to get out. Be sure to only drop one block for you and your villager to jump up on since two will suffocate you.

• A water source block (i.e. water bucket): You can place this outside the hole so that it flows into the hole, then swim up the waterfall. Be sure to pick the source up quickly after you swim out so your villager doesn't risk drowning.

• A boat, minecart, or bed: You can jump and place these outside the hole, then jump again to right-click on them, which will place you inside/on them and safely out of the hole. If you don't have any of these, but you do have the materials to craft them (along with a crafting table), then you can jump up to place a crafting table outside, jump up to right-click on it, and then make what you need.

• An Ender Pearl: Jumping up and throwing it will teleport you out of the hole. If you're patient you could even wait until night to lure a passing Enderman over and kill it for one.

• Saddled pig rescue: If there's a saddled pig nearby, or a nearby pig you could saddle, then jumping up and right-clicking on it will also get you out.

If you don't happen to have any of these items, I think your only hope is to position yourself just right so you can dig away at a wall block without hitting the villager's hitbox. Of course, you could also wait until you get killed by mobs or starve to death, then just respawn and return to free your villager.