Early identification of children at risk of developing reading difficulties is crucial for effective interventions. While orthographies and educational contexts differ, predictors included in early at-risk screening tend to remain rather homogeneous across countries. In this study, we compared longitudinal prediction patterns of being among the 20 percent lowest performing in reading fluency by the end of Grade 1 in Norway (N = 918) and Finland (N =378). The two countries differ in orthographic consistency (semi-transparent versus transparent), age at school entry and pre-primary education. Letter knowledge, phoneme isolation and rapid automatized naming (RAN) were unique predictors in the Norwegian sample. Predictors in the Finnish sample were gender, phoneme blending, RAN, and reading status. The predictive model identified significantly more Finnish than Norwegian poor readers (46.2% versus 27.9%). The results suggest national screening instruments that are sensitive to educational context and orthography.