Red Flag Warning
2025-12-20T00:00:00-07:00

...THIS IS A PARTICULARLY DANGEROUS SITUATION FOR IN AND IMMEDIATELY ADJACENT TO THE FOOTHILLS, BETWEEN 5500 AND 9000 FEET, FOR BOULDER AND JEFFERSON COUNTIES ON FRIDAY... Strong west winds, sustained 45-55 mph with gusts upwards of 85- 105 mph, are expected in the foothills of Larimer, Boulder and Jefferson Counties beginning early Friday morning. Relative humidity values are expected to drop into the low teens, possibly upper single digits. While Red Flag conditions, critical fire weather, are expected across a larger area in northern Colorado, the most extreme conditions are expected to be along Highway 93 from Jefferson County into Boulder County and along US-36 north of Boulder to the Larimer County line and westward. There will be a high potential for fast moving wildfires, should any new starts occur. Winds toward I-25 and eastward will be slower to develop, and also speeds will be considerably lighter. That said, gusts of 25- 40 mph are still expected to combine with very low humidity and cured grasses to support critical fire weather conditions. Such conditions may be a longer duration than usual, with potential for low humidity to extend well into the evening hours. * AFFECTED AREA...Fire Weather Zones 238, 240, 241, 242 and 243. * TIMING...From 10 AM this morning to midnight MST tonight. * WINDS...West 15 to 25 mph with gusts up to 60 mph possible west of I-25, and gusts to 40 mph possible along and east of I- 25. * RELATIVE HUMIDITY...As low as 12 percent. * IMPACTS...Conditions will be favorable for rapid fire spread. Avoid outdoor burning and any activity that may produce a spark and start a wildfire.


American River River Levels

Last Updated: December 19, 2025

The American River is a major waterway in California, running for approximately 120 miles from the Sierra Nevada Mountains to the Sacramento River.


Summary

Total streamflow across the American River was last observed at 1,090 cfs, and is expected to yield approximately 2,162 acre-ft of water today; about 48% of normal. River levels are low and may signify a drought. Average streamflow for this time of year is 2,289 cfs, with recent peaks last observed on 2016-12-16 when daily discharge volume was observed at 36,208 cfs.

Maximum discharge along the river is currently at the American River Near Nile reporting a streamflow rate of 1,090 cfs. This is also the highest stage along the American River, with a gauge stage of 74.64 ft at this location. This river is monitored from 2 different streamgauging stations along the American River, the highest being situated at an altitude of 2,789 ft, the American River Near Nile.

River Details

Last Updated 2025-12-19
Discharge Volume 2,162 ACRE-FT
Streamflow 1,090.0 cfs
-270.0 cfs (-19.85%)
Percent of Normal 47.62%
Maximum 36,208.0 cfs
2016-12-16
Seasonal Avg 2,289 cfs
       
River Streamflow Levels
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Streamgauge Streamflow Gauge Stage 24hr Change (%) % Normal Minimum (cfs) Maximum (cfs) Air Temp Elevation
American River Near Nile
USGS 12488500 		1090 cfs 74.64 ft -19.85
American R A Fair Oaks Ca
USGS 11446500 		1080 cfs 6.02 ft 0
Seasonal Discharge Comparison
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Maximum Streamflow Discharge
Streamflow Elevation Profile

The American River (Spanish: Río de los Americanos) is a 120-mile-long river in California that runs from the Sierra Nevada mountain range to its confluence with the Sacramento River in the Sacramento Valley. Via the Sacramento River, it is part of the San Francisco Bay watershed. This river is fed by the melting snowpack of the Sierra Nevada and its many headwaters and tributaries, including the North Fork American River, the Middle Fork American River, and the South Fork American River.
The American river is known for the discovery of gold at Coloma in 1848 that started the California Gold Rush and contributed to the initial large-scale settlement of California by European immigrants. Today, the river still has high quality water, and it is the main source of drinking water for Sacramento.
This river is dammed extensively for irrigation, flood control, and hydroelectric power. The American River watershed supports Mediterranean, temperate, and montane ecosystems, and it is the home of a diverse array of fish and wildlife.