Spring 2024 Frost/Freeze Info (we are declaring an "All Clear" on Frost/Freeze the rest of the spring!)

Before continuing, here are a few definitions...

South Central Nebraska and North Central Kansas
30-Year Average Last Frost/Freeze Dates (1994-2023)
(click images to enlarge)

Average Last 36° Date (Last Spring Frost) 1994-2023	Average Last 32° Date (Last Spring Freeze) 1994-2023	Average Last 28° Date (Last Spring Hard Freeze) 1994-2023

Median Dates of Last Spring Freeze & Hard Freeze (1991-2020)
(Midwestern Regional Climate Center)

Median Date of Last Spring 32° Freeze	Median Date of Last Spring 28° Hard Freeze

• The first column lists 10 locations in south central Nebraska and 3 in north central Kansas with long histories as NWS Cooperative Observer sites (except for Grand Island and Hastings airports, which are automated systems). This is just a small sampling of dozens of official weather stations within the NWS Hastings coverage area, and these sites are generally organized down the column from north-to south. 
   
• The second column shows the average date of the LATEST spring observance of 28°, 32° and 36° temperatures during the most recent 30-year period from 1994-2023.
   
• The third and fourth columns reveal the earliest last freeze date and latest last freeze date (32° or colder) over the last 30 years. It is readily apparent that the phrase "average last freeze date" is quite relative, as most sites feature a 5-9 week difference between the earliest and latest dates! For some of these locations, the incredibly-early last freeze of spring 2012 (between March 9-11) was among the earliest on record. On the opposite spectrum, for several places the latest freeze of the last 30 years occurred in mid-May 2014. 
   
• The final column is a recap of LAST SPRING (2023), showing the last dates that 28°, 32° and 36° were observed. A blue-shaded date indicates that the last spring frost/freeze/hard freeze of 2023 occurred at least 10 days LATER than the 30-year average, while red-shaded dates indicate a last spring frost/freeze/hard freeze that was at least 10 days EARLIER than the 30-year average. 

Spring Frost/Freeze Data For South Central Nebraska + North Central Kansas
(based on 30-year averages from 1994-2023)

The Midwestern Regional Climate Center (MRCC) produces maps that update DAILY, depicting the most recent date that sites across the region that have fallen to at least 32° or 28° this spring. In addition, GRAY shaded areas = places that have NOT YET accumulated at least 150 Growing Degree Days (GDD/base 50º F) since Feb. 1st.

This generally means that gray-shaded areas have not yet become favorable for widespread plant/crop growth that could be significantly damaged by frost/freeze, while white-shaded areas are more likely to feature vegetation susceptible to more widespread freeze damage. 

                                                                                                            (click images to enlarge Nebraska and Kansas maps)

KS: Most Recent  32° or Below This Spring (dots) and areas most prone to have vegetation damaged by a freeze (WHITE shaded areas)	NE: Most Recent  32° or Below This Spring (dots) and areas most prone to have vegetation damaged by a freeze (WHITE shaded areas)
KS: Most Recent  28° or Below This Spring (dots) and areas most prone to have vegetation damaged by a freeze (WHITE shaded areas)	NE: Most Recent  28° or Below This Spring (dots) and areas most prone to have vegetation damaged by a freeze (WHITE shaded areas)

The USA-National Phenology Network (NPN) produces several maps that update DAILY, depicting the progression of particular types of spring vegetation across the nation, and how it compares to long-term averages. See their web page for much more detail and information, but the two maps highlighted below depict First Leaf Index Anomaly and First Bloom Index Anomaly. In short, this means they show the current status of some types of spring vegetation (first leaf-out or first-flowering) compared to long-term averages, giving an idea of whether spring is "ahead" of or "behind" schedule. 

                                                                (click images to enlarge)

Spring Leaf Index Anomaly	Spring Bloom Index Anomaly