Marine heatwaves (MHWs) are extreme temperature anomalies that exist for a prolonged duration in the marine environment and pose significant threats to ecosystems and coastal communities through heat stress and the effects of severe weather events. For these reasons, the continuous monitoring and understanding of MHWs is integral for science, policy and management decisions. However, in coastal oceans and estuaries, where impacts are expected to be acute, large-scale data products typically used in MHW analyses are often too course to be informative. To address these issues, an integrated network of coastal observation platforms and high-resolution remote sensing data in the Gulf of America has been used to develop a regional MHW monitoring and analysis tool. The comprehensive interface on the Gulf of America Coastal Ocean Observing System [GCOOS) webpage provides both real-time and historical statistics for MHWs and along with flexible event detection based on daily thresholds, monthly thresholds, and degree heating weeks. Additionally, the tool incorporates satellite temperature anomalies and the ability to define MHWs based on user needs, while displaying characteristics of notable events at each location. The improved monitoring of MHW events has the potential to greatly improve the relevance of monitoring to managers and stakeholders interested in the nearshore environment, and to provide marine data relevant to the complex and multidimensional interactions between a warming climate and habitat health, citizen science, and socio-economic monitoring.