How Weather Conditions Affect the Whitetail Rut
November 01, 2016
The whitetail hunting world is bursting at the seams with myths and black magic. We're all guilty as charged, adding fuel to the fire in deer camps each season, oftentimes under the influence of adult-flavored truth serum after a long day's sit in our favorite tree.
One year we share a personal experience among hunting buddies; the following year it becomes deer law.
"I spilled coffee on my boot this morning. I was in my stand for just 5 minutes when a 10-pointer followed my coffee trail right to me!" Next thing you know, Cabela's is selling Folgers next to buck urine.
Perhaps the most popular debate among whitetail hunting theorists revolves around weather, especially as it relates to the rut. You can pontificate about how weather conditions influence rutting activity until your blaze-orange turns blue — and maybe you'll be correct. But if you want to know what three of the most hardcore, expert whitetail hunters think, now's your chance.
Dr. Harry Jacobson
Let's start with the science. Dr. Harry Jacobson is a matter-of-fact whitetail biologist who has built his entire career around whitetails. He has a PhD in Wildlife and Fisheries Ecology, and he privately manages 40 properties for big-game hunting, with a major focus on whitetails.
Dr. Jacobson is just as likely to be found revising a research paper as he is butchering a buck. He has killed countless whitetails in his years as a biologist and hunter.
Today, he focuses primarily on bowhunting mature deer that are almost impossible to kill. It's no coincidence that he plays close attention to weather conditions, and he loves to hunt during the rut — a time when even the wisest whitetails make fatal mistakes.
"Weather isn't going to affect the rut very much. The rut's going to happen regardless of weather conditions," Dr. Jacobson explained. "Deer get bred on almost the same day every year. The peak of the rut can change a little bit from nutrition — maybe as much as a week — but it's going to happen, rain or shine. Does are programmed to cycle into estrous depending on their internal clock every year, and it's both influenced by genetics and photoperiod. Shortening days will get the cycle rolling."
While there's no stopping the rut, it's daylight deer movement that hunters care about most, and weather conditions certainly play a role in this.
According to Dr. Jacobson, deer-tracking studies have proven that changes in barometric pressure affect deer movement. Typically, when the barometer starts to drop, deer are on their feet. Research has also shown that high temperatures ("high" is relative to your location) result in more nocturnal activity, and heavy winds or intense rainfall will keep deer hunkered down. But not all moisture is bad: A slow, drizzling rain usually gets deer on the hoof.
Continuing on the topic of temperature, Dr. Jacobson said there's no doubt that cooler temps encourage bucks to move more during daylight. His favorite way to hunt whitetails is to rattle them in. He has brought hundreds of fight-ready bucks into bow range by banging antlers together, and he noted how temperature factors into his rattling strategy.
"Bucks can be very receptive to rattling, particularly during the pre-rut. Deer are going to respond to antlers much later in the morning on cool days versus warm days."
Dr. Jacobson rattles aggressively, moving 200 to 300 yards at a time until he gets a response. He will usually go through three crashing cycles in one sequence, waiting a couple of minutes between sequences.
But realize, rattling works best in areas with a well-balanced buck-to-doe ratio, and where there is a solid supply of mature bucks. You might be able to rattle in a pile of rutting bucks at your rich uncle's ranch in southern Texas, but odds are you won't get the same results on Grandpa's back 40 in northern Minnesota.
What about the moon phases?
"Despite all the hype, there has been literally no research to demonstrate that moon cycle has anything to do with deer movement or the rut," Dr. Jacobson said.
His final words of wisdom: "As a whitetail hunter, the bottom line is that you need to be in the field during the rut. Regardless of weather conditions, there's going to be heightened deer activity."
Since he was four years old, sitting in his father's camouflaged lap, Cy Weichert has spent every fall chasing whitetails. After more than 30 years observing and studying deer, he has come to the conclusion that understanding weather conditions is paramount for planning a hunt. He also realized there was no serious weather forecasting service designed specifically for hunters, so he built one — it's called ScoutLook.
Now, more than 800,000 deer hunters are using ScoutLook's free website and mobile apps to up their odds of putting venison on the table.
Weichert's fascination with weather began in his teens, when he noticed that he was seeing more deer during periods of wet snowfall or cold, light drizzle.
"Back then, I thought deer maybe just liked the feeling of cool moisture on their face, or the silence of wet leaves," he explained. "I had no scientific knowledge then, and no idea that this really has to do with high humidity conducting heat away from a deer's body. To compensate, they increase activity in high humidity and low temperatures. All I knew was it was my favorite time to be in the woods, and still is!"
He was quick to point to wind as the most important factor to pay attention to when heading to your favorite whitetail haunt.
"We built ScoutLook's ScentCone Wind Map because you can't beat a whitetail's nose," Weichert said. "It gives you a visual wind forecast for 72 hours, hour by hour, at any of your treestands or ground blinds. You should almost always set up your hunting situation for the wind to be in your face. And you need to be aware of how thermals will alter wind direction based on terrain during calm, clear evenings at sunset. On calm, northern early season days when the air is cold and the ground is still warm, you can ignore the wind in the mornings because the thermal effect of heat rising from the ground will keep your scent above the deer."
When hunting for mature bucks, Weichert uses very high-risk wind tactics that most hunters would never try, he explained.
"I've learned that most wise, old bucks will circle downwind of my position when called in, and after getting busted dozens of times, I developed a strategy that I call the 'death curl.' I set up 180 degrees opposite of normal upwind shot strategies and plan for bucks to circle, so my shooting lanes are set just before they step into my ScentCone. I also use attractant as my ally. Before I climb into my stand, I lay down Tink's 69 lure on the edges of my ScentCone, in my shooting lanes, to catch the buck's nose and stop him just before he catches my human odor. If that doesn't work, I mouth grunt to stop him."
Weichert has taken on the nickname of "Grunt Man" because of his extremely realistic natural-voice deer-calling abilities.
Regarding temperature, barometric pressure and precipitation, Weichert sides with Dr. Jacobson. But when it comes to moon phase, he sees things differently.
"With the mystique of the moon as the driver of all things bizarre, from werewolves to lunatics, it's fitting that there's so much hubbub about its effects on deer movement," he said with a grin. Weichert grew up harpooning swordfish and tuna on the high Atlantic. "The moon absolutely has a big effect on fish and game activity — probably a lot bigger than most people think," he noted.
"I kept a log of every swordfish and giant tuna seen over a 12-year period, and I saw three times more fish during a waning crescent moon. I affectionately named this quarter phase the 'tuna-tail moon,' given its likeness in shape. I don't think we'll ever get the facts of it nailed down like we have with wind, but some hunters such as Joe Miles and Adam Hayes have a system that delivers with amazing consistency.
"I've always kept my moon theory practical. I never let the moon keep me out of the woods, but I hunt the tuna-tail moon phase and new moon phase religiously."
Killing any whitetail is a major accomplishment, but how about more than 400? That's the running tally for Dan Perez, CEO of Whitetail Properties, and 50 of those were bucks that meet the minimum score for Pope & Young Club classification.
"I don't golf. I don't bowl. I hunt whitetails. It's what I do," he said without a second thought. "It's not one season — it's all year long. Planting food plots, cutting trails, hanging stands, hinge-cutting trees '¦ it's my life."
Perez grew up whitetail hunting in Florida, but since then he has traveled across the United States and killed deer in a number of states. Today, he resides in Illinois, where a reputable number of trophy-class mature bucks are killed annually. Perez has encountered almost every imaginable type of deer herd, and just about every weather condition under the sky.
So, what part of a weather forecast does Perez pay closest attention to? Temperature.
"The one trend that I see related to deer activity is temperature swings," he said. "If there's a 10-degree drop in temperature, you'd better be in the woods because all hell breaks loose. I've been most successful when there has been a significant drop in temperature, no matter where I am in the country."
Perez mentioned that he waits to hunt his best honey-holes until there's a major front with a notable dip in the mercury.
"I don't want to alert the animals that I intend to kill," he said. "If they don't know they're being hunted, it's so much easier to kill them." He mainly focuses on killing mature bucks, so every effort to stay off their radar can pay massive dividends.
Of course, Perez also noted the importance of setting up according to wind conditions. "I like a steady breeze in one direction," he explained. "In a perfect world, it's between 5-10 mph. When it gets up to 15-20 mph with gusts of 30, I don't like it. And if the wind switches, I get out of there fast."
He went on to describe an interesting way to test wind currents and how your ScentCone interacts with the terrain — sometimes in very unexpected ways.
"I don't do it much anymore because of fire dangers, but I like to release a smoke bomb in the woods," he said. "I've had spots where that puff of smoke leaves my stand, goes through the woods, circles around and comes back to me — no matter what the wind direction is! If you see a deer blowing and it appears your scent isn't traveling directly at the animal, there's a good chance it is '¦ you just don't know it."
Lastly, he advised that consistency is the most important aspect of playing the wind. "If you see leaves falling in multiple directions, that's a bad situation," he said.
In terms of the rut, Perez's decades of personal observations fall in line with scientific research when it comes to weather's influence on this magical time of year.
"The does have to be bred," he said. "No matter the weather conditions, bucks will be taking care of business."
However, he does alter his setup strategy during the rut to remain undetected and get in the hot zone.
"I'm way more sensitive to the wind during the rut," he explained. "I hunt ridgetops because they connect bedding areas, and bucks will cruise these ridges with their nose in the air, just trying to get a nostril full of everything that's going on."
These cruising bucks are seeking hot does, no doubt, but their heightened sense of awareness means an increased likelihood of busting stinky human predators.
Perez also believes that cloud cover can be an important ally during the rut.
"The rut and deer movement in general is heavily influenced by the amount of available light," he said. "When there's significant cloud cover, it makes mornings last longer and evenings come faster. An overcast sky also keeps it cooler earlier and later. Deer react by staying on their feet longer during shooting light.
Like Dr. Jacobson, Perez doesn't bark at the moon.
"I've hunted every moon phase and every transition in between," he said. "Contrary to how most people feel, I'm not convinced that the moon affects hunting one bit — during any part of the season. I've had as much activity during a full moon as I've had on a no-moon.