Data from Public Health England, published by Northumberland County Council, reveals the county-wide infection rate was 156.4 per 100,000 on December 16.
This compares with the England-wide rate of 206.6.
However, large areas of west Northumberland and pockets in the south-east have significantly higher case rates which will have contributed to the decision to keep the county in Tier 3, the toughest level of Covid restrictions.
Several different criteria are being used to determine which areas are in which tier: case rates in all age groups, case rates in the over 60s, the rate at which cases are rising or falling, positivity rate (percentage of tests which come back positive), and pressure on the NHS.
Here are the 14 Northumberland wards with Covid rates above the national level.