Rivermatics

USGS Streamgage 11290000

Tuolumne River A Modesto, CA

Tuolumne River A Modesto, CA is USGS streamgage 11290000 in California, monitoring river discharge in hydrologic subbasin 18040009. It drains a watershed of about 1,884 square miles. Discharge records at this site go back to 1895. Typical flow runs near 273.4 cfs in July and 729 cfs in April, with the higher of the two arriving in April. Rivermatics issues a daily machine-learned flow outlook for this gauge, reaching 14 days ahead.

View live conditions & forecast →

Gauge details

State
California
Drainage area
1,884 sq mi
Gauge elevation
3 ft
Subbasin (HUC-8)
18040009
Coordinates
37.62715, -120.98438
USGS site number
11290000
Records begin
1895-01-01 (131 years)
Rivermatics forecast
14-day flow outlook

14-day flow forecast

Based on observations through for Tuolumne River A Modesto, CA. Each day carries a median estimate and the band the model expects the flow to fall within — not a single number to plan against. Forecasts are re-issued daily; see the live screen for the current outlook.

Forecast daily mean discharge in cubic feet per second, by date
Date Low p10 Expected p50 High p90 Range
189 210 226
184 213 237
181 213 243
176 212 247
170 212 249
166 210 251
159 208 251
156 208 255
152 207 258
144 204 257
142 205 263
139 203 262
140 204 265
138 204 271

All values in cubic feet per second (cfs). Estimates only — do not use them for navigation or for any safety, rescue, or emergency decision.

Typical flow by month

Long-term daily discharge percentiles from the USGS record (up to 86 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.

Historical monthly discharge percentiles in cubic feet per second
Month Low p10 Typical p50 High p90 Range
January 204.2 818.1 4,499.7
February 214.3 1,028.1 5,063.8
March 219 845.8 6,136.1
April 238.6 729 6,708.3
May 193.9 670.5 6,201.9
June 117.7 312.8 5,292.3
July 111.9 273.4 1,736.9
August 118.9 266.2 875.3
September 120 272.7 1,012
October 169.9 530.7 1,456.4
November 196.1 498.1 1,695
December 197.2 733.9 2,661.6

All values in cubic feet per second (cfs).

Common questions

When does Tuolumne River A Modesto, CA normally run highest?
February, on the long-term record. The median daily flow that month is about 1,028.1 cfs, against 266.2 cfs in August, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
What is a normal flow for Tuolumne River A Modesto, CA?
It depends on the month. In January, half of days historically fall near 818.1 cfs, with the middle 80% of days between 204.2 and 4,499.7 cfs. The month-by-month table on this page gives the full range.
How long has Tuolumne River A Modesto, CA been measured?
Discharge records at USGS site 11290000 begin in 1895, about 131 years, covering roughly 9,130 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
Is there a flow forecast for Tuolumne River A Modesto, CA?
Yes. Rivermatics trains a machine-learned model — a temporal-fusion transformer — on this basin's observed flows, weather, and snowpack, and issues a daily flow outlook reaching 14 days ahead: a median estimate inside a confidence band, not a single number to bet on. Every forecast is scored against days the model never trained on, and that track record is published on the live gauge screen. Open live conditions to see the current outlook.
Where is Tuolumne River A Modesto, CA?
The gauge sits at 37.62715, -120.98438, in California, in hydrologic subbasin 18040009, at an elevation of about 3 feet, draining roughly 1,884 square miles.
Can I use Tuolumne River A Modesto, CA data for flood or safety decisions?
No. Rivermatics provides estimates, not guarantees, and the readings and forecasts here may be delayed, inaccurate, or wrong. Do not use them for navigation or for any safety, rescue, or emergency decision. Check the National Weather Service and USGS directly, and use your own judgment.

Other gauges in this subbasin