Cold-weather stiffness is usually caused by the ball head’s internal design and materials. Two likely reasons came up: lubricants (oil/grease) can thicken or effectively freeze at low temperatures, and different materials in the ball and socket may contract at different rates, increasing friction. In practice, lubricant-related stiffness is a common cause.

What you can do:

• Test the head in a freezer (sealed in a plastic bag first) to confirm the behavior while avoiding condensation or ice.
• If it uses grease or oil, performance may drop a few degrees below freezing.
• Look for grease-free or oilless ball heads if you regularly shoot in sub-zero conditions; these are generally much better in the cold.

Are there models that avoid this? Yes—higher-quality heads and designs intended to work without heavy lubrication tend to remain usable in very low temperatures. Community experience suggests some premium heads stay smooth in winter conditions where cheaper or heavily lubricated ones may seize up.