Based on a revised and extended multi-station Hawaiʻi Temperature Index (HTI), mean air temperature in the Hawaiian Islands has warmed significantly (p = 0.0007) at 0.05°C/decade over the past 100 years. Significant warming trends for the last century are evident at low (0.056°C/decade, p < 0.001) and high elevations (0.047°C/decade, p < 0.01). A comparison of changes in mean temperature between Hawaiʻi’s Mauna Loa Observatory and Spain’s Mt. Izaña Observatory, both above the local trade wind inversion (TWI) and both experience windward orographic clouds trapped below the upper-level TWI at ~2,000 m, are similar and suggest rapid warming above the TWI for these tropical high mountain islands. Read the by Marie Mckenzie.