The COVID-19 outbreak entailed radical shifts to individuals’ daily habits that challenged their subjective well-being (SWB). Knowledge about the impact of COVID-19 on SWB is paramount for developing public policies to tackle mental health during health emergency periods. Decreases in life satisfaction are likely not only due to exposure to daily negative emotions but also due to hopelessness, fear, and avoidance of social interactions. We examined in a sample of 541 Spanish adults (1) reactions to the COVID-19 outbreak and (2) the mediating role of these reactions in the associations of hope and social phobia with life satisfaction through different levels of positive and negative affect. A moderated mediation analysis showed that the conditional indirect effect of hope and social anxiety on life satisfaction through information depended on the participants’ having high positive affect and low negative affect. Affect seems to be a mechanism that modulates the influence of individuals’ perception about COVID-19 on their life satisfaction. Those with high positive affect might see the “general picture” and search for adequate information as they avoid focusing on the problem and on specific information that precludes preventive behaviors. Having a positive affect might help individuals to adopt information-processing strategies during the COVID-19 outbreak that will improve their life satisfaction.