To climb Kilimanjaro, a heavy down jacket is mandatory.

Summit night can be dark, extremely windy and brutally cold. While temperatures may be mild, perhaps 20°F to 30°F (-7°C to -1°C), you should be prepared for much harsher conditions. We have had instances where nighttime temperatures were as low as -20°F (-28.89°C) with wind chill. So your down jacket and overall layering system has to be warm enough for you to endure this environment for hours, with no break or shelter.

Your summit success may come down to how well you handle the cold. In this article, we’ll cover how to choose the right down jacket, how to layer it correctly (most people get this wrong!), and how to actually use it on the mountain.

Choosing a Down Jacket for Kilimanjaro

Here is what we recommend for a Kilimanjaro down jacket.

• Look for a fill power of 650-800. The higher the fill power, the warmer the insulation.
• Aim for a fill weight of 200-300 grams. This is the weight of the down only, not the weight of the entire jacket. Avoid down “sweaters” or “ultralight” jackets – they are not warm enough.
• Your jacket should have an attached, insulated hood to shield your head from wind.
• Nice features include hand pockets, a chest pocket and inside pockets.
• Find a jacket that can be stuffed and packed into its own zippered pocket for convenience and portability.
• Make sure your down jacket fits over all other layers including your shell. It is not used as a midlayer.

How to Layer a Down Jacket

Many people think all down jackets are supposed to be worn as a midlayer, under the hardshell. That seems logical. Down is insulation and shells block weather. But that only works for thin, lightweight down jackets – not the robust down jackets required for climbing Kilimanjaro.

A heavy down jacket is not a midlayer. It’s an outer layer. You don’t wear it under your hardshell. You wear it over everything. That includes your base layer, soft jackets (fleece), and hard shell.

There are several reasons why a down jacket is worn over the hardshell:

• Wearing a down jacket underneath another jacket compresses the insulation. That reduces the loft, which in turn reduces the warmth. Down works by trapping air. If you smush down feathers under a shell, you strip its insulating properties.

• Shuffling layers exposes you to the cold. Taking off the hardshell to put on a down jacket requires time and energy, but most importantly it allows body heat to escape in the process. Doing this repeatedly would be inconvenient, inefficient, and unnecessary.

• A hardshell that is big enough to fit over the loft of a big down jacket would be impractically oversized. That would compromise the fit and function of the hardshell for the rest of the climb.

Practical Use of a Down Jacket

On Kilimanjaro, you will likely use your down jacket in the evenings. Before the sun goes down, you can throw your down jacket on to stay warm while relaxing or eating at camp.

If you feel cold in your sleeping bag, wear your down jacket to bed for added warmth.

While hiking, it’s usually too warm to wear a big down jacket. But on summit night, if it is extremely cold, you might find it comfortable to wear the down jacket even while you climb.

The most common way to use the down jacket on summit night is during breaks. You stop, put it on, and retain heat while inactive. Then when it’s time to move, you take it off again.

The key is to be aware of conditions, be adaptable, and regulate your layers accordingly. You don’t want to be hot or cold.