Boulder ties driest water year; reservoirs enter October at 76%

Boulder recorded 10.65 inches of precipitation from October 2025 through September 2026, tying water year 1965–66 for the city’s driest on record, a comparison reported by Axios and attributed to Peter Goble of Colorado State University’s Colorado Climate Center. NOAA’s 1991–2020 annual average is 21.16 inches, making this water-year total about half that amount.

Reservoirs entered October at 76% of capacity, 12 percentage points below the reported 88% seasonal average. Axios reported Boulder considered storage sufficient for the next few months, a near-term assessment rather than a guarantee about later conditions.

The city remains in Drought Watch and encourages voluntary conservation, including reducing or turning off lawn irrigation as conditions allow. Boulder monitors water supply, weather and drought conditions and says it will update its status if it changes. Its annual May 1 supply evaluation considers mountain snowpack, reservoir storage and available Colorado-Big Thompson water. Axios reported the city planned to reassess conditions in spring 2027.