When should you switch from trail runners back to waterproof or insulated hiking boots when the temperatures drop in autumn? I get asked this question frequently and it’s something I wrestle with myself every autumn. The easy answer, is when temperatures drop below freezing (32 degrees) during the day or night. But there are a lot of mitigating factors and transition strategies that you can employ to defer switching from trail runners to boots. Some are more comfortable than others, some less so.
Day Hiking in Autumn
For example, if you’re day hiking, you can usually wear trail runners down to freezing, provided:
- You can keep your shoes and socks dry.
- There’s no wind.
- You don’t stop for breaks often or stand around on cold rock.
- You hike at a fast pace and generate a lot of body heat.
- You eat snacks and stay hydrated.
- You don’t have to wear metallic traction aids like microspikes.
Unless you know your intended route and hiking partners well, it can be difficult to predict these factors. For example, it’s easy to underestimate the amount of water that fallen leaves can hold in autumn, even if it’s not raining, or the increased wind exposure you’ll experience when hiking through forest after the leaves have dropped. The same holds for morning frost or dew which can make your shoes and socks wet, or the cold that radiates up through your trail runners if you have to wear a metallic traction aid to hike over slick and icy rock.
You can mitigate all of these conditions by wearing a waterproof insulated sock from SealSkinz or a Hanz Chillblocker Waterproof (Hanz is a subsidiary of SealSkinz). The added insulation, wind protection, and waterproofing will keep you reasonably comfortable in your trail runners down to freezing or lower. Another alternative is to wear oven bags over or under wool socks, which is less expensive, but also less insulating.
Regular hiking or insulated winter boots are usually much warmer than trail runners in borderline weather, because they don’t have mesh sides and they have much thicker soles. This results in much greater wind resistance and more foot and sole insulation. Personally, I switch from trail runners to lightly insulated winter boots (200 g of insulation) without ever wearing regular hiking boots, because I don’t own any. “Waterproof” winter boots with synthetic insulation will also stay warmer if you get them soaked, while the same can’t be said of uninsulated or leather hiking boots.
Backpacking in Autumn
Backpackers have to consider the same factors that day hikers do, plus nighttime temperatures, and the weather over the course of several days. It’s one thing if your shoes get wet on a day hike, because you can go home and dry them out by the wood stove. But if you’re on a multi-day backpacking trip, wet trail runners are likely to freeze at night if temperatures drop below 32 degrees. There’s also less of a chance to recover from wet shoes during a multi-day trip in freezing weather, unless you can hit town and dry your footwear out completely.
There are several ways to mitigate the risk of frozen trail runners. One way is to sleep with them and prevent them from freezing with your body heat. This can be uncomfortable as hell, but it does work. Another way is to rewarm your shoes in the morning by putting a hot water bottle or heat pack in them to melt any ice that’s formed overnight. But they’ll likely to still be cold when you put them on and your feet will struggle to warm them up.
Surrender to the Inevitable: Boots
If none of these mitigating strategies sound very appealing, it’s because they’re not. If you hike in the colder and wetter weather that often accompanies autumn, you will want to switch to boots if temperatures consistently drop below freezing. While boots aren’t as lightweight or comfortable as trail runners, it is what it is. Look at the bright side. You’re still hiking and spring will get here eventually.