This dataset includes sample information, vesicularity by pycnometer, grain size and shape data by CAMSIZER, and measurements of crushed and thin section mounted grains by microscope. All studied samples were from scoria and air-fall-tephra deposits (most formed in Hawaiian lava fountains) collected around the summits of Mauna Loa and Kīlauea volcanoes, Island of Hawaiʻi. These data were used to derive methods for quickly being able to quantify vesicularity in near-real-time during an eruption response. The samples from Kīlauea all erupted from the summit area and include Keanakākoʻi units B, D, E, K1, and K2, the Halemaʻumaʻu eruptions in September 2021 and September 2023, and the Kīlauea Iki eruption that formed the Puʻupuaʻi scoria cone. A single sample from the summit of Mauna Loa from the 1949 scoria cone was also used for this study.