80305 Weather -- Boulder, CO
Overview
80305 -- South Boulder and Foothills Neighborhoods, CO
Zip code 80305 is Boulder's southernmost and highest-elevation zip, covering the south Boulder foothills neighborhoods of Shanahan Ridge, Bear Creek, and the broader South Boulder area. Average elevation here is around 5,580 feet, with Shanahan Ridge reaching 5,710 feet -- the highest residential elevation in the city.
The entire 80305 zip borders South Boulder Creek Open Space to the west and south, creating a direct wildland-urban interface along much of its extent. Weather here is more intense than in the lower, sheltered Boulder valley: snowfall is heavier, Chinook winds stronger, and afternoon thunderstorms faster-developing due to the proximity to the south Boulder foothills.
The South Boulder Creek corridor and extensive open-space trail system make 80305 a prime outdoor recreation zip, with the NCAR Trail, Bear Creek Trail, and Flatirons Vista trailheads all accessible within a short drive or bike ride.
Fire Risk and History
80305 has a high wildfire risk. The entire zip borders South Boulder Creek Open Space on the west and south, placing most of the residential area within Boulder's wildland-urban interface zone. The grass and shrubland fuels on the adjacent foothills slopes are highly flammable under the dry Chinook wind conditions common in autumn and spring. The December 2021 Marshall Fire -- which burned 6,026 acres in neighboring Louisville and Superior -- was driven by the same Front Range downslope wind pattern that affects 80305. While the Marshall Fire did not enter 80305, the wind conditions were virtually identical to scenarios that could drive fire into these neighborhoods. The City of Boulder's Wildfire Mitigation Program provides defensible-space guidelines specifically relevant to this zip.
Elevation and Microclimate
| Elevation | 5580 ft |
| Zip Code | 80305 |
| County | Boulder County, CO |
| Wildfire Risk | High |
| FEMA Flood Zone | Zone X |
At an average of 5,580 feet -- and up to 5,710 feet at Shanahan Ridge -- 80305 is Boulder's highest-elevation zip code. The elevated foothills position produces measurably different weather than the lower valley: snowfall totals run 30–40 percent higher than downtown Boulder, frost is possible across a longer season, and Chinook wind speeds are among the strongest in the city. Summer afternoon thunderstorms develop rapidly along the foothills above the zip, and lightning is a real concern for residents hiking or biking adjacent open-space trails.
Flood Zone Information
80305 is classified FEMA Flood Zone X with minimal flood risk for the residential areas of the zip. The elevated terrain drains rapidly away from homes, and there is no major floodplain within the developed portions of 80305. The South Boulder Creek corridor in the open space below and west of the residential area does experience periodic flooding and trail closures during significant storm events, but these do not affect the upslope homes. The September 2013 regional flood event produced notable flows in South Boulder Creek but left 80305 neighborhoods unaffected. Verify specific parcel flood zone at FEMA's Flood Map Service Center.