frost bit

when i left home this morning a bit before four to go to work there was no frost on the ground or the windows of my vehicle...people at work were talking of heavy frost in their areas so after work i motored over to campus and i found some rather frost damaged spuds ( top two photos)...they will recover since it was not a hard freeze but the setback will take time to overcome...sill no great problem...when i got home i wandered into the back yard and found spuds completely untouched by frost damage in any way ( bottom three photos )...this has me wondering about the intricacies of microclimate...i know altitude provides a variety of climates as you go up hills and mountains but the garden and my back yard are pretty much lead level and only about six or so miles apart as the crow flies...i see more research and reading ahead.