West Nile Virus in Colorado
As of September 2026, Colorado has 4 West Nile Virus alerts in the past 30 days (4 confirmed cases).
Risk Level
🟠 Elevated
Multiple cases — enhanced biosecurity recommended
Cases (30 days)
4
Total Cases
19
Counties Affected
10
Most recent West Nile Virus alert in Colorado: Sep 10, 2026
West Nile Virus Alerts in Colorado
Pueblo, Colorado
Sep 10, 2026 · active
1
confirmed
Montrose, Colorado
Sep 10, 2026 · active
1
confirmed
Morgan, Colorado
Sep 4, 2026 · active
1
confirmed
Weld, Colorado
Sep 1, 2026 · active
1
confirmed
Weld, Colorado
Oct 29, 2025 · active
1
confirmed
Mesa, Colorado
Sep 30, 2025 · active
1
confirmed
Weld, Colorado
Sep 12, 2025 · active
1
confirmed
Weld, Colorado
Aug 14, 2025 · active
1
confirmed
Montrose, Colorado
Aug 12, 2025 · active
1
confirmed
Las Animas, Colorado
Aug 5, 2025 · active
1
confirmed
Douglas, Colorado
Jul 3, 2025 · active
1
confirmed
Prowers, Colorado
Oct 31, 2024 · active
1
confirmed
El Paso, Colorado
Oct 8, 2024 · active
1
confirmed
Douglas, Colorado
Sep 25, 2024 · active
1
confirmed
Douglas, Colorado
Sep 11, 2024 · active
1
confirmed
Weld, Colorado
Aug 30, 2024 · active
1
confirmed
Larimer, Colorado
Aug 22, 2024 · active
1
confirmed
Larimer, Colorado
Aug 22, 2024 · active
1
confirmed
Pueblo, Colorado
Aug 19, 2024 · active
1
confirmed
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