From September 9th - September 16th, 2013, Colorado experienced one of its most extreme rainfall and flood events in recorded history. How did this storm compare to other major rain/flood events in Colorado history? Check out the Historic Events page to learn more information about previous events.

A "perfect" combination of moisture, instability, and a slow moving system provided everything needed for this event. Visit the Meteorology page to learn more about how this storm started and evolved.

88 stations (with at least 10 years of data) recorded a record 24-hour precipitation total during this storm event. Visit our Extremes page to read more about records broken during this storm.

The U.S. Drought Monitor improved drought conditions across most of Colorado after the rains and floods. Visit the Drought page to read more details about drought improvement in mid-September.

The Satellite page highlights some of the interesting satellite imagery that was taken durin the rain and flooding event. This image shows water vapor moving into the region on September 11th and September 12th.

Hourly precipitation accumulations across the northern Front Range. Visit the Hourly Accumulations page to read more specifics about hourly accumulations across the region throughout the entire storm event.

We're looking for any measurements of the storm! If you took any sort of unofficial measurement, we'd like to know. If you have photo evidence, even better. We'd also like to know your stories during the flood. Email us at

Storm Factsheet
Historic rains and flooding affected 6 major rivers/tributaries, 14 counties, and over a dozen cities/towns in Colorado. Go to Timeline and Impacts page for more information on counties and cities affected by the storm.

Recovery efforts are already underway and CDOT announced it will have roads fixed or temporary roads in place by December 1st. Find more information on our Resources page.

The Boulder cooperative observer recorded a storm total of 17.15 inches, shattering several records: the daily record (with 9.08"), the monthly record (currently at 17.24"), and the annual record (currently at 30.20").

Initial recordings show the South Platte at Fort Morgan, CO peaked near 50,000 cfs (cubic feet per second) due to the storm. This is much higher than its normal peak runoff values during the spring snowmelt runoff season. See more runoff details here.

Areas within the storm's epicenter received over 600% of average precipitation for September 2013. Visit the Storm Totals page for more info on precipitation totals.

During the period Sep. 10th - 15th, the Boulder NWS Office issued 64 Flash Flood Warnings and 38 Flood Warnings.