Flagstaff Braces for Overnight Freeze and Frost Risk

Temperatures expected to dip below freezing along I-40 early Monday morning

Apr. 3, 2026 at 10:04am

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A sweeping, atmospheric landscape painting in muted tones of gray, white, and blue, depicting a vast, frozen expanse under a dramatic, cloudy sky. The scene conveys a sense of the overwhelming, sublime scale of the natural world, with the frozen ground and vegetation dwarfing any small, isolated structures or vehicles.A sudden late-season cold snap blankets the Flagstaff region in a frozen, atmospheric landscape.Flagstaff Today

The National Weather Service has issued a weather alert for Flagstaff, Arizona, warning of a freeze and frost risk overnight. Temperatures are forecast to drop into the mid-20s Fahrenheit, creating the potential for icy patches on roads and frost on surfaces. Drivers are advised to be cautious, especially on bridges and shaded areas, while residents should protect sensitive plants and check outdoor plumbing.

Why it matters

Sudden drops in temperature can pose a significant threat to public safety, infrastructure, and local agriculture in the Flagstaff region. This late-season cold snap comes after a period of warmer weather, which may have encouraged early spring growth that is now at risk of damage.

The details

According to the National Weather Service, clear skies and calm winds have allowed temperatures to fall near 28°F early, with lows dipping closer to 25°F in surrounding areas. These sub-freezing conditions increase the risk of frost and icy patches on untreated surfaces. Across Flagstaff and along I-40 and I-17, drivers should stay alert for isolated slick spots, especially on bridges and shaded roadways. Residents will notice the cold immediately stepping outside, with frost potentially coating vehicles, rooftops, and vegetation.

  • Temperatures have already dropped into the 20s early Monday morning.
  • The freeze and frost risk is expected to last until around 9 AM Monday.

The players

National Weather Service

The federal agency responsible for weather forecasting and issuing weather alerts and warnings.

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What’s next

Temperatures are expected to rebound quickly, reaching the mid-50s by this afternoon. The warming trend is forecast to continue through the weekend, with highs in the low to mid 60s.

The takeaway

This late-season cold snap serves as a reminder for Flagstaff residents to be prepared for sudden changes in weather conditions, especially as the region transitions from winter to spring. Protecting sensitive plants, checking outdoor plumbing, and exercising caution on the roads will be crucial in the coming hours.