In 2023, wildfires led to widespread destruction of property and displacement of residents in Alberta and Nova Scotia, Canada. Previous research suggests that wildfires increase the psychological burden of impacted communities, necessitating population-level interventions. Cognitive Behavioural Therapy (CBT)-based text message interventions, Text4HopeAB and Text4HopeNS, were launched in Alberta and Nova Scotia, respectively, during the 2023 wildfire season to support the mental health of impacted individuals. The study examines the effectiveness of Text4HopeNS and Text4HopeAB in alleviating psychological symptoms and improving wellbeing among subscribers. The study involved longitudinal and naturalistic controlled trial designs. The longitudinal study comprised subscribers who completed program surveys at baseline and six weeks post-enrolment, while the naturalistic controlled study compared psychological symptoms in subscribers who had received daily supportive text messages for six weeks (intervention group) and new subscribers who had enrolled in the program during the same period but had not yet received any text messages (control group). The severity of low resilience, poor mental wellbeing, likely Major Depressive Disorder (MDD), likely Generalized Anxiety Disorder (GAD), likely Post-Traumatic Stress Disorder (PTSD), and suicidal ideation were measured on the Brief Resilience Scale (BRS), the World Health Organization-5 Wellbeing Index (WHO-5), Patient Health Questionnaire 9 (PHQ-9), Generalized Anxiety Disorder 7 (GAD-7) scale, PTSD Checklist-Civilian Version (PCL-C), and the ninth question on the PHQ-9, respectively. The paired and independent sample -tests were employed in data analysis. The results from the longitudinal study indicated a significant reduction in the mean scores on the PHQ-9 (-12.3%), GAD-7 (-14.8%), and the PCL-C (-5.8%), and an increase in the mean score on the WHO-5, but not on the BRS, from baseline to six weeks. In the naturalistic controlled study, the intervention group had a significantly lower mean score on the PHQ-9 (-30.1%), GAD-7 (-29.4%), PCL-C (-17.5%), and the ninth question on the PHQ-9 (-60.0%) which measures the intensity of suicidal ideation, and an increase in the mean score on the WHO-5 (+24.7%), but not on the BRS, from baseline to six weeks compared to the control group. The results of this study suggests that the Text4Hope program is an effective intervention for mitigating psychological symptoms in subscribers during wildfires. This CBT-based text messaging program can be adapted to provide effective support for individuals' mental health, especially in the context of traumatic events and adverse experiences such as those induced by climate change. Policymakers and mental health professionals should consider these findings when shaping strategies for future disaster response efforts, emphasizing the value of scalable and culturally sensitive mental health interventions.