The calculated distance (air line) between Al Ḩudaydah and Ḩajjah is approximately 76 miles respectively 122 kilometers.
By car or train, the actual journey to Ḩajjah is certainly longer, as only the direct route (as the crow flies) between Al Ḩudaydah and Ḩajjah has been calculated here.
Air line (approximately)
122 kilometers
66 nautical miles