Wisconsin Frost Laws & Spring Thaw Limits

How Wisconsin handles spring thaw

Wisconsin posts spring thaw restrictions by frost zone, usually late February through late April, re-declared every year (Wis. Stat. § 348.17). On Class II state highways your overweight permits go void and you're capped at the 80,000 lb legal load. The bigger hit is local: counties and towns sign their own 'X ton' seasonal limits, and that posted sign is the law on that road. Check WisDOT's map and the local authority before hauling.

Window, reduction, and where to check

• Season: Declared by WisDOT frost zone (five zones) each spring, usually late February or early March once the frozen-road period ends, running into late April. In 2026 the last zones cleared April 30. Dates move every year.
• Reduction: No flat percentage cut on legal loads. On Class II state highways (about 12% of the system) your divisible-load overweight permits are suspended, so you're held to the 80,000 lb legal max. Counties and towns separately post their own 'X ton' seasonal signs, and that sign is the limit on that road.
• Interstates: Exempt from the seasonal reduction
• Find the current order: WisDOT seasonal weight restrictions page and interactive map, or the recorded status line (608) 266-8417. WisDOT covers only the state highway system, so check the county and township road authorities for the local roads too.
• Overweight penalty: Overweight forfeiture on a per-pound-over scale (Wis. Stat. § 348.21). A first conviction runs a $50 to $200 base plus 1 cent per pound up to 2,000 lb over, stepping through 3, 5 and 8 cents, and topping out at 15 cents per pound once you're more than 5,000 lb over. A second conviction inside 12 months raises the base to $100 to $300 and the top rate to 18 cents per pound. A seasonal overload is enforced as a standard overweight violation.

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