Spring frost and freeze climatology

Warming temperatures and recent rounds of rainfall have allowed perennial grasses, flowers, shrubs, and trees to start re-emerging across the Central Plains and much of the Midwest. While it may be time to start working in the yard again, those looking to sow seeds for a warm season garden or set out ornamental annuals should do so with caution as a damaging spring freeze could still be in the cards.

Climatologically, the last subfreezing spell of the season takes place between April 15th and April 30th across Northwest Missouri and Northeast Kansas. This range of dates is based on 30 year averages, and can vary widely from year to year. For example, the last freeze of the season in St. Joseph has taken place in early April for the past two years; April 8th in 2025 and April 5th in 2024. However, the final freeze of spring 2023 was almost a month later on May 3rd.

Beyond subfreezing temperatures, accumulating snow can also show up well into the spring season locally and regionally. Earlier this week, several inches of snow fell in southwest Iowa overnight, adding up to 5 inches in Creston Iowa by day break on April 7th, with an inch of accumulation reported as far south as Putnam County Missouri. 

The most memorable local spring snow in recent history was in 2013, when several inches of wet snow accumulated in parts of Northwest and North Central Missouri on May 3rd. That same year, the last freeze of the season in St. Joseph was on May 12th!

This month's most recent shot of subfreezing temperatures at Rosecrans Airport in St. Joseph was April 5th. It’s possible that this was indeed the final “freeze” before the growing season kicks off, but those looking to plant cold sensitive vegetation should pay close attention to the forecast over the coming weeks. 

If a frost advisory or freeze warning is issued, have a plan to protect plants from frost by covering them up or taking them indoors. If that’s not feasible, it may be wise to wait a few more weeks to finish planting your warm season garden.