This dataset is used in the following study: "Recurrent Rossby wave packets modulate the persistence of dry and wet spells across the globe." Dataset includes: Dry and wet spells for the Northern and the Southern Hemisphere respectively. The output of the statistical model for each season (MJJASO/NDJFMA) and for each spell type (dry/wet) for both the hemispheres (NH/SH). File naming used belongs to mainly two categories: one for naming spell file, and second for naming the output file from the statistical model. An example from each category is explained below. The rest of the files follow the same naming style. Spell file; NH_1.0mm_dry_spells_all_months_gap_1_days_no_spell2_check.nc: Northern Hemisphere 1.0mm threshold dry spell for all months with a gap of 1 day Statisical model output file; NH_weibull_MJJASO_drythresh_1_min_spell_count_40_time_steps_min_spell_length_5D_1D_N_1980_2016.nc: Northern Hemisphere Weibull model output for MJJASO using dry threshold of 1.0 mm with a minimum spell count of 40 time-steps and a minimum spell length of 5 days for the period 1980-2016 This dataset alone is sufficient for reproducing the analysis presented in the study. Open source tools like Python, R, etc can be used to read '.nc' file type. Additional code help in the form of Jupyter notebooks reproducing figures made from this dataset can be viewed here on GitHub.