Why Do Manhole Covers Sometimes Explode in Cold Weather?
What It Is
In cold weather, some manhole covers are suddenly pushed upward or blown off.
What’s Under the Street
Manholes cover underground utility systems.
These spaces can contain steam, hot water, or warm air.
Why Cold Weather Matters
Cold air cools the metal cover.
This creates a strong temperature difference.
How Pressure Builds
Steam forms underground from heat sources.
If vents are blocked, pressure increases.
Why the Cover Moves
Pressure looks for the weakest exit.
The heavy cover can be forced upward.
Common Examples
- Steam rising from streets in winter
- Covers shifting during cold snaps
- Urban areas with steam systems
Closing Summary
Manhole covers can explode in cold weather when steam pressure builds underground and is suddenly released.
