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December 11, 2025

Red flag warning in effect through 5 p.m. Thursday

The National Weather Service in Boulder has issued a Red Flag Warning for an area including eastern Boulder County and Louisville. Gusty winds and low relative humidity values will create conditions favorable for rapid fire spread along the lower foothills, I-25 corridor, and adjacent plains through this afternoon. Gusts up to 45 mph will be possible. Please avoid outdoor burning and any activity that could produce a spark.

What is a Red Flag Warning?

The National Weather Service will issue a Red Flag Warning when there’s an increased risk of fire danger. A Red Flag Warning means that the conditions are right for the start or rapid spread of wildfires, and that extra precautions should be taken to prevent them. Low humidity, strong winds, and dry fuels pose an increased risk of fire danger, prompting heightened fire awareness and safety precautions.

What you should do on Red Flag days:

• Avoid any activity that may produce a spark and start a wildfire. This includes avoiding open burning, avoiding mowing operations or dragging chains, or operating any equipment that produces sparks or has open flames. 
• On Red Flag days, residents should be prepared for possible power outages. Xcel Energy (our power provider in Louisville) may have Public Safety Power Shutoffs or be using Enhanced Powerline Safety Settings on Red Flag Days. Learn more about how to prepare for power outages on Boulder County's website.