Spearfish holds the world record for the fastest recorded temperature change. On January 22, 1943 at about 7:30 a.m. MST, the temperature in Spearfish was −4°F (−20°C). The Chinook wind picked up speed rapidly, and two minutes later (7:32 a.m.) the temperature was +45 °F (+7 °C) above zero. The 49 °F or 27 °C rise in two minutes set a world record that still holds. By 9:00 a.m., the temperature had risen to 54 °F (12 °C). Suddenly, the chinook died down and the temperature tumbled back to −4 °F or −20 °C. The 58 °F or 32.2 °C drop took only 27 minutes. The sudden change in temperatures caused glass windows to crack and windshields to instantly frost over.