On March 21, these Houston County wildflowers were caught in full bloom. On that date, the National Weather Service (NWS) in La Crosse, Wis., noted that a stretch of record-breaking temperatures began on March 10, and well above normal temperatures could continue for another week.

"As a result of the unprecedented warmth, green-up has started well ahead of schedule," a NWS spokesman wrote, adding that gardeners should beware of the possibility of frost later this spring.