The Hawaiʻi Messonet: A 100-Station Real-Time Weather and Climate Monitoring Network across Hawaiʻi's Steep Gradients

Weather forecasting, climate modeling, resource management, and atmospheric, hydrological, and ecosystems research all require comprehensive, accurate, and timely meteorological data. Hawaiʻiʻs recent extreme weather events resulting in catastrophic flooding, e.g., Kauaʻi – April 2018, and wildfires, e.g., Maui – August 2023, illustrate the critical need for spatially distributed and comprehensive weather data for emergency management. Historically, the climate observing network in Hawai‘i has been fragmented, unmanaged, and inadequate to meet these needs. Hawaiʻi’s mountainous terrain, multi-island geography, and steep climate gradients make weather monitoring particularly challenging. To meet this challenge, we are deploying the Hawai‘i Mesonet as a statewide network of around 100 telemetered weather/climate stations, each with sensors for rainfall, air temperature, relative humidity, wind speed, wind direction, four components of net radiation including solar radiation, soil moisture, soil heat flux and soil temperature, providing 5-minute data transmitted every 15 minutes. The goal of the Hawaiʻi Mesonet is to produce high quality, high spatial and temporal resolution data, and make it freely available to all non-commercial interests. The project is on track to complete the installation phase by around the end of 2024.