The study aimed to determine the effectiveness of the blended learning modalities used by teachers in teaching Environmental Science classes in the new normal and their relationship to their academic performance. The researcher utilized the descriptive-correlational design and employed the random sampling technique. The respondents of the study were the 81 education students of Negros Oriental State University from the chosen campuses. The researcher employed validated questionnaire and with Cronbach's Alpha reliability coefficients of greater than 0.70 in all areas. The researcher used percentage, mean, weighted mean and Spearman Rank Order Correlation in treating the data. The study revealed that the extent of effectiveness of the blended modalities in terms of (a) content, and (b) instructional design and support of learning materials is "very high" while (a) organization and presentation, and (b) assessment of learning materials is considered "high". On the other hand, the extent of effectiveness of the blended modalities in terms of feedbacking and evaluation of students' work as part of the teachers' role is noted to be "high". Meanwhile, the academic performance of students is classified as "good". Furthermore, the content of the learning materials and the feedbacking of the teachers are contributory to the students' academic performance.