Lockdown and unlock for the COVID-19 pandemic and associated residential mobility in India

•Residential mobility increased from the baseline percentage during the lockdown and unlock periods.•Across India, residential mobility increased by 26.9% during lockdown phase 1 (March 25 to April 14, 2020).•Residential mobility increased the least in the north-eastern states of India and also in the eastern and extreme northern states of India.•Going from phase 1 lockdown to phase 4 lockdown and during the unlock period, the units or percentage of residential mobility decreased.•About 31.5%, 30.8%, 26.2%, 23%, 17.6%, and 18.2% of the increase in residential mobility from pre-lockdown phase are observed during lockdown phase 1, 2, 3, 4, and unlock 1.0, 2.0 in India respectively. [Display omitted] As an outcome of the Coronavirus 2019 (COVID-19) pandemic, the countrywide lockdown and unlock periods altered residential mobility trends in India. The aim of this study was to investigate the impact of the COVID-19 lockdown and unlock periods on residential mobility trends, using the spatial time-series daily changes across the different states and union territories of India. This study was based on time-series data of the daily percentage change in residential mobility from baseline in India. Conditional formatting techniques, box plotting, time-series trends plotting methods, and spatial kriging interpolation mapping techniques were employed to show residential mobility trends. Increases in residential mobility of approximately 31.5%, 30.8%, 26.2%, 23%, 17.6%, and 18.2% from the pre-lockdown period were observed during lockdown phase 1, phase 2, phase 3, and phase 4, unlock 1.0, and unlock 2.0, respectively, in India. This was due to people moving towards home or their place of residence during the COVID-19 pandemic in India. From the time lockdown was initiated up until July 31, 2020, residential mobility increased the least in the north-eastern states of India and also the eastern and extreme northern states of India. The results of this study could be used in public health strategies towards decreasing the spread of COVID-19.