If the weather is bad, that doesn't mean that a good barbecue is off the table. You can pull 20-hour smokes in sub-zero temperatures with great success. The secret to operating a charcoal or wood-burning smoker is vigilance. When the weather is bad, you simply have to be extra vigilant.
Smoking in cold temperatures presents several challenges. When operating a charcoal or wood-fired backyard smoker, the weather is always an important factor. As temperatures drop, you need to be diligent to make sure your smoker maintains temperature. Wind, rain, and other precipitation add further obstacles, but with some prep and patience, you can smoke during almost any weather.
The first thing to consider is the temperature difference between inside your smoker and outside your smoker. On a nice warm summer day, you might find that your smoker has an internal temperature of around 100 F before a fire is even lit. If your target temperature is 225 F, you need a fire that will increase in smoker temperature by 125 F. However, if it is a cold and overcast day, the internal temperature of your smoker could be 35 F or even less, meaning you need to increase the temperature by quite a bit more. This means warm weather makes for better temperature control and a hotter fire inside your smoker.
Wind is another important factor when considering temperature control. When attempting to mitigate the effects of wind, consider the wind direction. Some smokers, like the large offset smokers, have a definite airflow path. Air comes into the smoker through the firebox and moves across the cooking chamber and out the stack. If the wind is blowing in this direction, the increased airflow will burn your fuel faster and can cause high-temperature spikes. This means you’ll need to keep the vents closed more than normal.
If the wind is going in the other direction, it can stop the airflow entirely and keep the heat out of your cooking chamber. It is best to let the wind add to the airflow rather than stopping it. If possible, position your smoker so that the wind is blowing in the same direction as the smoker's natural airflow. On a windy day, you'll need to keep a closer eye on the smoker's internal temperature.
Of course, it's very difficult to smoke in heavy rain regardless of the temperature, but cold weather can also bring light rain or snow. When water hits your smoker, it evaporates, and evaporation pulls heat from your smoker. If it begins to rain or snow while you are smoking, it’s time to open up the vents and bring up the temperature to offset this heat loss. Keep a close eye on it to make sure you're hitting your optimal temperature.
Strategies for Counteracting Weather
The ideal smoking environment is a warm and calm one. Anything you can do to create this environment will help you maintain good temperatures and have a successful barbecue.
By positioning your smoker in a sheltered (but not enclosed) space, you can reduce the effects of wind and rain. Some people have gone so far as to build windbreaks to set around their smokers to keep the wind away. This can be a good strategy, as long as you are not putting flammable material close to your smoker. The wind can carry sparks a good distance.
Some home cooks use insulation materials to hold the heat in their smokers. This strategy can be safe and effective as long as you're using flame-resistant materials. You can typically find fire-resistant insulation or water heater blankets at your local hardware store. Cut to fit around your smoker, these materials can hold in a great deal of the heat. Just make sure you don't cover up the vents.