Analyses of time series data for bottom or near bottom temperatures for 50 stations distributed throughout Long Island Sound reveal distinctive features of the bottom water temperature history during the lobster mortality event of 1999. These include: temperatures that exceeded 23.5°C in shallow, well-mixed areas; markedly higher temperatures, in general, in those areas with water column depth <20 m; basin-averaged bottom temperatures that were the highest for the decade during the months of July and August; and a rapid increase in bottom temperatures in late August caused by the vertical mixing of warm surface waters during a strong wind event. Results indicate that anomalies in the local surface heat flux made an important contribution to bottom temperature anomalies.