Results of teacher assessments at the end of Key Stage 1 show a larger percentage of children achieved the target in reading, writing and maths.
In reading, the proportion went up to 80% from 78% in 2016 and in writing 74% achieved the target compared to 70%. The proportion in maths rose from 76% to 79%.
The proportion scoring the expected standard in science fell to 86% from 87%.
Pupils are assessed in the four subject areas by their teacher at the end of Year 2 in school. Schools in Northumberland are ahead of the national average in all topics.
Assessments were made for 3,332 pupils in state-funded schools across the area.
Girls performed more strongly than boys and the gap was widest in writing, where girls were 11 percentage points ahead. In reading, 84% of girls achieved the target standard compared to 77% of boys, and 36% were judged to be working at above the required level.
The data also reveals the attainment gap for children from disadvantaged backgrounds, measured by looking at the scores for those receiving free school meals.
Only 65% of these children reached the reading target and in maths it was 62%.
Key Stage 1 assessments were introduced in 2016 to examine how children were coping with the more challenging national curriculum set by government and the increase in standards expected.
Coun Wayne Daley, cabinet member for children’s services at Northumberland County Council said: “These figures are fabulous news – and congratulations must go to all pupils, teachers and families who have helped to achieve them.
“This council wants to see excellent results and outcomes for all children and young people in Northumberland and making improvements in education across the county is our top priority. We will be working with schools and partner organisations to bring about fundamental change to the whole lifelong learning system, from early years right through to higher education and beyond.”