Here again is an illustration of the idea that water helps you instrument your nano-climates (yes, that’s a word I made up). The melted zone — marked “← Why? →” is a readout, but I can’t interpret it! Why is the melt zone the width that it is? (For a moment, I thought the melt zone was caused by the reflection of afternoon sunlight downward from the side of the house onto the earth, and was congratulating myself for having correctly foreseen happiness for the cantaloupe seedlings to be planted in that bed, but the angle of the sun doesn’t explain why the right-hand boundary of the zone falls where it does.)

So I know why the melt zone begins at the foundation and moves right: That’s the thermal mass of the stone walls of the basement pushing heat outward in the earth. (And that’s a good thing, because otherwise we’d have the freeze/thaw cycle nestling right next to the brick wall, and that would crack the mortar, then the brick. And that would be bad.)

But why does the melt zone end on the right at the drip line? Look at the elevation profile: Drops from the drip line have been digging a moat or canal or trench parallel to the house, which fills with water, which absorbs heat that would otherwise keep spreading right. Thermal mass again! Maybe this nano-climate is a little like the “lake effect”?