Meteorological winter is officially in the rearview mirror! Looking at the data, if you thought it was a warm one, you're correct! Overall, it was the 8th warmest winter in Kentucky history (data back to 1895), bookended by the 11th warmest December and 4th warmest February ever recorded. We weren't alone either. Looking at the map below of statewide temperature ranks, absent from the southeast, nearly everyone across the U.S. landed in the top-10, which resulted in the warmest winter ever recorded for the continental United States.

These warm winters have been nothing new to the Bluegrass State. In fact, seven of the past ten winter seasons have run above normal in Kentucky. The more eye-opening stat is that all seven are among the top-20 warmest winters ever recorded. Six of the those are in the top-10 (table above)! Bottom-line, our climate is definitely trending warmer. As I've been telling folks in presentations across the state, we all need to take a step back and think about how warmer winters will impact your own operation in the future. We're all weather nerds, but we need to be climate nerds, too, and think long-term!

Head start to the 2024 Growing Season

The warm winter has led to a head start on the 2024 growing season as trees are blooming, grass is growing, and unfortunately... I already spotted a mosquito on my arm last week! How far along are we? One way to track vegetative or pest development is by calculating heat units or, in other words, growing degree days (GDDs). Just like last year, we've been accumulating GDDs at a very rapid pace in 2024. The base temperature required for growth will vary among different crops, but in the graph below, I used a base temperature of 32 when calculating GDDs.

As of March 12th, Bowling Green has accumulated 934 GDDs. Only two years have exceeded this number at this point in the season over the past decade, 2017 and 2023. In other words, it makes a lot of sense that we're seeing so much growth. This is just one example across the state, but everyone is ultimately in the same boat.

While it's nice to see vegetation coming to life early in March, it's not necessarily a good thing. For one, this leaves a lengthy period of susceptibility as frost and freezing temperatures will surely come back into the picture. Unfortunately, this will be the case next week. More info below.

Secondly, pests are starting to make their 2024 debut. Eastern Tent Caterpillars are the latest addition to the list (more info, here). Alfalfa Weevil will also be here before you know it... maybe already. Below is a look at the latest map of GDD accumulations across the state (base temperature of 48 for development of this pest). As Dr. Bessin (UK Extension Entomology Specialist) explains in this 2023 article, scouting is recommended once your county hits 190 degree days. Some counties in Western and South-Central are approaching or already surpassed this threshold. Many more will exceed this threshold today after getting into the 70s. The model can be accessed, here. In addition, Dr. Bessin lists some tips on delaying and preventing pesticide resistance for this particular pest, here.

One last downside of the early spring temperatures is the return of crabgrass and spring weeds. Soil temperatures are running well above normal for this time of year, leading to crabgrass getting ever so closer to germination. Recently, I talked with Kenneth Clayton, a UK Extension Associate in Turfgrass. He mentioned that while germination will start when 2-inch soil temperatures get to 57-64 degrees, it's best to go ahead and spread your pre-emergent herbicide now, to give it time to get worked into the soil. You ultimately want to have it down when you see a 5-day average soil temperature between 50 and 55 degrees. This data can be checked out for a location close to you through the Kentucky Mesonet. I just looked up the data for Fayette, and let's just say... I better get the spreader out!

Kenneth talked about this subject and controlling other spring weeds in a podcast with Warren County's Horticultural Extension Agent, Kristin Hildabrand. Check it out, here. In addition, you can also read Extension pub, AGR-272 (Preemergence Herbicides for Kentucky Lawns), for more information.

Forecasts and Outlooks

Our warmth from February has carried over into the month of March. As of 4 PM Eastern on March 13th, we are currently sitting in the low to mid 70s across the state, about 15 degrees above normal for this time of year! Will the warmth continue? Looking ahead, we peak tomorrow (3/14) with highs in the mid to upper 70s. Then we start going in the downward direction. It all starts with our next rain-maker, set to arrive tomorrow and Friday. In terms of total accumulations, models still haven't quite come together for this system, but it looks like a decent bet the highest totals will be across the southern half of the state where a half to one inch is on the table. Some severe weather will also be possible, mainly for Western KY, where the Storm Prediction Center currently has a slight risk (highest threat = damaging winds).

Behind a cold front, we see temperatures return to seasonable norms this weekend with highs in the middle 50s to low 60s. The downward trajectory continues into next week when we'll likely see below-normal temperatures in place. This is very much highlighted in the 6-10 day outlook below. We'll see highs struggle in the 40s at times and lows bottom out in the 20s (coldest on Tuesday morning). Upper teens will even be in play for some of those valley locations across Eastern KY. Again, normal highs for this time of year run in the middle 50s to low 60s, while lows average in the middle to upper 30s. Outside of the cooler temperatures, we're looking at a mainly dry forecast.

Related News from UK and Beyond

Using Prediction Models to Manage Diseases in Fruit - Cheryl Kaiser, UK Plant Pathology Extension Support, and Nicole Gauthier, UK Plant Pathology Extension Specialist

Kentucky Forage News - March 4, 2024

Kentucky Beef Cattle Newsletter "Off the Hoof" - Beef IRM Team, March 7, 2024

Slugs are Active in February 2024, but Farmers Have Two Registered Molluscicides under Section 24(c) in Kentucky - Dr. Raul Villanueva, UK Entomology Extension Specialist, and Zenaida Viloria, Extension Research Analyst

Corn N Timing Research - Dr. John Grove, UK Agronomy/Soils Research & Extension, and Dr. Edwin Ritchey, UK Extension Soil Specialist, January 13, 2023

Vegetable Production Guide for Commercial Growers, 2024-25 (ID-36) - Cheryl Kaiser, UK Plant Pathology Extension Support, and Nicole Gauthier, UK Plant Pathology Extension Specialist, February 6, 2024

March edition of the KY Monthly Climate Perspective on Drought and Hydrologic Conditions - Kentucky Climate Center, March 7, 2023

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