Teachers experience significant stress with 93% reported high levels of stress (Herman et al., 2018), and literature examining teacher stress levels during the COVID-19 pandemic reveals that 30 percent of teachers experience significantly high levels of stress (Silva et al., 2021). Low levels of teacher well-being and higher levels of stress have been linked to punitive behavior management (Jennings & Greenberg, 2009) and lower student academic achievement (Goddard et al., 2000). The aim of the present study is to explore the relationship between teacher emotion and use of evidence-based instructional strategies that promote student success. In this study, 17 first-year teachers completed a novel measurement, inclusive of single-item scales intended to assess feelings of stress, efficacy, and school connectedness, several times a day, each day of the week, for 1 month. The classroom strategies assessment system of evidence-based academic and behavioral instructional strategies was used in weekly teacher observations. Results indicated validity between these single-item scales and established measures of teacher well-being. A positive relationship between teachers' in-the-moment well-being and evidence-based instruction was found, as well as substantial variation in teacher emotional response across days and weeks. Implications and future directions are discussed.