Cold fronts: The key to killing whitetails

Cold fronts: The key to killing whitetails

Sep 30th 2019

Time to burst your bubble; for the most part, the rut occurs at the same time in your area each fall, meaning that the full moon does not trigger the whitetail doe estrous cycle. Too many of us, including myself, get so carried away with rut indicators and moon phases that we forget a key influence on whitetail activity, that being weather. I have used moon guides and seen varying results, but to date, the only foolproof method to get whitetails on their feet is a substantial cold front. I know, we all want to look online and see the“best days to hunt”each fall, but in reality, it’s a bunch of BS. The rut occurs at the same time each year, and while lunar phases play a role in whitetail activity, weather dictates daytime movement above all else. Experts do not completely rule out the effects of the moon because at certain phases it is believed that it does have an impact on whitetail movement, but there is no correlation between the timing of the rut and the full moon. Cold fronts are the key to killing whitetails.

Every five years or so, we experience a rut that seems to be weaker than years past. Much of the time the lack of daylight activity is blamed on the moon phase, a hot doe a few farms over, or hunting pressure. However, the decrease in activity is typically not a result of the moon or a dwindling population; it is that the temperature is above average and activity has shifted to after dark. Want proof? Last year was “one of those years” in the midwest. Rumors of the worst rut in a decade were being spread across the Midwest, and while some good bucks were taken, a lot of hunters were left scratching their heads. Last years temps are pictured in the graph below, you can see that the first three weeks of November were unusually warm. Above average temperatures could explain why whitetail movement was below average and the rut appeared to lack its typical intensity. This data is from an area that I hunt in western Wisconsin, and I will agree that deer activity dwindled to a frustratingly low level. The average temperature in Wisconsin during the first two weeks of November is typically around 45 degrees, last falls temps soared into the mid to upper 60’s.

On the contrary, the fall of 2015 brought below average temperatures and the activity was explosive during the typical rut time frame. That fall, I shot two mature bucks within a 5-day window at the end of October. The first on the evening of October 25th and the second on the night of October 30th. If you correlate the dates with the Weather Underground graph below, you will notice three identifying weather characteristics, the temperature was below average, barometric pressure was high or rising, and wind speed was very low on the evenings of both kills.

It was no fluke that these two bucks were up and moving on those dates. The weather played a major roll in my success that fall and I was tagged out in two states before Halloween.

Late October of 2015

Here are three weather conditions that will influence deer movement. When 2 or 3 of them occur, whitetail movement will typically increase:

Temperature drop:10 Degrees is good, 15-20 degree drops are great. If you see this in the forecast, hunt.

Wind speed reduction:When the wind speed is above 25 mph for over 12 hours, wait for it to subside, even if it is only a 10mph drop. Deer rely heavily on sight and sound to detect predators. When it is windy, a whitetail’s sense of sight, sound, and scent is limited; they will hunker down. After the front passes, they will be up and moving to make up for lost time, especially during the rut.

High pressure:Look for pressure readings in the 30.1-30.25 range. Pressure readings are not an exact science, but high barometric pressure tends to increase movement.

For most of us, the cold front theory creates a problem when deciding what dates to play hooky from work. We cannot predict weather patterns months in advance which makes it difficult to narrow down when to be in the field. On the bright side, a lot of weather stations can now predict fronts as far as ten days out. These forecasts are valuable to the hunter who plans to take time off of work around an impending weather system.

The chance to kill a big buck heightens between October 25th and November 15th, so wait to hunt your best stands until everything is just right. If the weather is ideal during this timeframe, it will be your greatest window to see a mature whitetail on his feet during shooting hours. Specifically, you are looking for days with colder than average temps, a high barometer, and low to moderate winds. Cold fronts can also be a deadly tactic in the early season. The first substantial autumn cold front is undoubtedly a time you should try to be near a food source. If acorns are dropping and a cold front is sliding in, chances are deer will beat you to the oak tree.

For those of you that abide by the lunar calendar, experts believe that there is a connection between the full moon and deer activity. The full moon causes a lot of strange occurrences in nature, whether triggered by available light or gravitational pull, the moon does have a direct influence on wildlife and alters typical behavioral patterns. If we apply the moon theory to the 2015 and 2016 outcomes discussed above, in 2015 the second full moon of the fall equinox was Oct. 27, in 2016 it was on Nov. 14. The full moonmayhave had an influenced towards my success in the small window at the end of October in 2015. We have been compiling data for the past four years and plan to launch a moon application that better documents the influence it has on whitetail activity. To date, not enough data has been collected to show definitive proof that there is a direct correlation.

Bottom line, the rut occurs at the same time each year, but there are certain influences that affect the intensity that we see. Both the moon and cold weather play a role in daytime sightings, but the latter should hold greater value to the hunter. Simplify your hunting strategy this fall and watch the weather. You can count on an autumn cold front moving through every 5-7 days and if you choose to hunt around the front, you will see a lot more whitetail activity.

The Weather Underground history tab is an invaluable resource. Weather Underground allows you to look back at weather history to better distinguish temperature, pressure and wind patterns. By documenting your hunts, you can begin tocorrelatecertain weather “indicators” thatincreaseor decrease whitetailmovement.

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