Guides

• How Cold Before Pipes Freeze? The 32, 20, 10 and 0 Rule — Pipes freeze at different outdoor lows depending on where they run. The four thresholds, why 20F is the usual rule, and how many of 3,140 US counties reach each.
• Why Pipes Burst in Places That Rarely Freeze — 762 US counties get only a few nights below 20F a year, and houses there are often not built for them. What the data shows and what to do.
• Insulate or Heat Tape? What Foam Sleeves Actually Prevent — Foam-sleeving a pipe moves its freeze point from about 20F to 10F. Across 2,938 counties that reach 20F, here is where that is enough and where it is not.
• When Freeze Season Starts and Ends, by Latitude — The usual first and last 32F nights across US counties, from NOAA normals, and why the date to be ready by is earlier than the first hard freeze.
• How the County Freeze Numbers Are Made — How PipeFreezeNights turns NOAA station normals into a figure for each of 3,140 counties: station blending, the elevation correction, match grades and known weak spots.