Hempstead Lake, NY

As of 2026-10-12, Hempstead Lake sits at 21.59 ft, which is above average for this time of year. Over the past 30 days the level has risen 0.04 ft.

The most recent reading at Hempstead Lake is 21.59 ft (2026-10-12), sourced from the U.S. Geological Survey. Readings on this page refresh automatically as the agency publishes new data.

The highest level for Hempstead Lake in our records is 23.81 ft on 2023-12-12. The lowest is 18.23 ft on 2022-09-30. Our record covers about 4 years of readings.

Compared with every October in our records, the current level is higher than 74% of them, which we classify as above average for this time of year. Seasonal comparison matters more than the raw number, because most reservoirs draw down predictably through late summer and refill over winter and spring.

Reservoir levels move for four main reasons: rainfall and runoff into the basin, releases through the dam for downstream water supply, power generation or flood control, evaporation during hot months, and seasonal drawdown schedules set by the operating agency. Hempstead Lake has risen 0.04 ft over the past 30 days. For the operational reason on any given week, check the U.S. Geological Survey directly.

Hempstead Lake is +1.66 ft compared with this date last year (21.59 ft today). The full-history chart above covers 4 years, with a record high of 23.81 ft and a record low of 18.23 ft.