This study investigates the relationship between changes in the frequency of dwell time delays and passenger flow characteristics and the frequency of railway service during the COVID-19 pandemic. To do so we make use of automatic passenger count data from commuter trains in Southern Sweden. Our findings show that the frequency of dwell time delays decreased under COVID-19 conditions compared to the two years prior, but dwell time delays did not cease to exist altogether. The improvement in dwell time performance is found to occur for delays of 30 s and larger, whereas the occurrence of delays up to 15 s increased. No decline in the service frequency under COVID-19 conditions was found. Overall an improvement in dwell time punctuality can be observed under COVID-19 conditions. The analysis, somewhat, points towards a reduction in peak passenger loads to be one of the factors associated with this improvement. This is, however, not the sole reason as dwell time punctuality is found to improve for all volumes of boarding passengers. The lower passenger demand thus improved dwell time punctuality under COVID-19 conditions, but it does not tell the whole story. When trying to improve dwell time punctuality it is thus not sufficient to only reduce the number of passengers boarding, but other measures are necessary as well.