Bald Paul

I've found that it's impossible to cover every part of my body to keep it warm when it's cold outside. Even if I can keep my core comfortable, my face, ears, hands and toes will all become unbearably cold.
In the heat, I can always stop somewhere shady, have a good drink from my water bottle, and cool down. Stopping to warm up just isn't an option. You just get colder.

staehpj1

I like cold weather. I don't like hot weather. I can acclimate to either, but the cold weather really doesn't require much effort for me to get used to.

That said I am in Tallahassee, but MTB ride at dawn so I am on trails at the coolest part of the day. So despite being in Florida it doesn't get super hot on my rides. I do get plenty of mornings in the 30s F and some in the 20s F. Rarely it even hits the teens F.

If anything I miss the colder weather and the snow from when I lived up north. I did tend to trail run and snowshoe more when I lived up north though.

As far as performance, It was moderately cold for here this morning (34 F) and I did my fastest time for one of my normal trail loop rides by a comfortable margin. When it get colder in the winter I don't slow down at all. When it gets hot I might need to get acclimated to get back up to speed.

Wilbur Bud

I think there are two aspects to the question, one is general effect of temperature and in my experience the available cold spectrum slows you down more than the heat. But I think the flavor of the question is more about the effect of temps at max performance/effort and so my commuting data is not so interesting. I would agree if you are on a training ride or racing, then the heat will have more of an impact because it will knock you out. Below chart 10 years old I think, but it was 5 years of data from daily year-round commuting. Old man, recumbent, bags, lights, fenders, laptop, tools, etc. I love the heat and never had a problem, even about 100°F but it was only an hour each way on average. No correction for wind but you can see the huge variation.

mharri24

+1 for slowing down in the cold! I'd much rather take off layers and need extra liquids than pile on the layers and have iced-out boogies.

wolfchild

I don't really care how extreme heat or extreme cold affects performance or how uncomfortable it may feel. Weather won't prevent me from getting outdoors and riding. Completing a hard ride in sub-optimal conditions always feels great afterwards, far better and more enjoyable than any Zwift or indoor session.

2Mins2Midnight

Living in Texas and being a bit cold-blooded, I've always preferred riding in hot weather over cold. After racing every Thursday night during the hottest summer on record (temps were usually 96+ degrees at start) this past year, however, my tune may have changed a bit. It took me several weeks to figure out nutrition because short track racing in that kind of heat is really hard on the body and my gut was always in knots after each race. I finally had things figured out by the end of the summer, but this was the first time where the heat has really had such a strong effect on me. But I still hate riding in the cold!

rsbob 

What slows me the most is a brewery serving ‘cold ones’ on a sweltering hot day.

Yan 

This is pretty definitive and puts the question to bed as far as I'm concerned. I was arguing for heat being worse but data is data. End of story.

Quite surprising that you don't hit peak speed until above 80F. For me that would be well into the discomfort zone. I guess discomfort sensation does not exactly reflect power output.

Korina

Since you didn't say the poll was for just roadies, I voted slow regardless. "Heat" here is different from what most of you experience; we hit 75F three or four days last August so we had several windows open. Not hot enough to slow me down; not hot enough to slow anyone down. Cold (invariably with 70%+ humidity) does slow me down, just because of all the layers. Not being a roadie, and definitely being a weather weenie, under 32F I don't ride.

Eyes Roll

Extreme cold weather, or cold weather; it's not even close. I rode my bike quite a few times in extreme cold weather that numbed the fingers of my hands and legs with two pairs of winter gloves on and two pairs of socks on, one upon another.

I also rode my bike in extreme heat in a country (not US) where it is quite normal for people to die in summer as a result of heat stroke. Extreme heat there did not make me as much uncomfortable as extreme cold in the US did. I also think the heat in the US summer is never extreme, at least to me, having experienced the extreme heat of the summers outside the US.

I hate US winters, the months from December to March, in general, and look forward to the months from April to November, so that I can get out and do some outdoor activities like biking, hiking, running, or even walking.

Wilbur Bud

Well, take care on a couple points with the conclusions.

I think the chart is good for only one basic conclusion, that for normal everyday riding that cold slows you down.

I would avoid validating the peak speed at 80°F remark because this is Excel and so the trendline choices are limited, in this case a linear polynomial, and really my expectation is that with a better model like a rational polynomial then the knee in the curve would be much sharper and lower down, more like 60°F and really I would expect a very slight slope, almost flat, from 60°F upward. When I was first looking at this data 10 years ago my expectation was that the sharp dropoff due to cold would start more around 25°F so I was quite surprised to see it beginning at a much warmer temperature due to I do not really wear anything more than shorts and a jersey until we get down in the mid-to-low 50's.

I think if we could extend the data range in the upper half, say to 120°F or 130°F then yes there would be a huge dropoff/disaster because the body core would overheat at some point. Similarly if the duration of the ride was extended long past my average one-hour commute, say to four or six hours, then again I think the heat would bring a big dropoff or stoppage due to you just cannot take the heat stress forever whereas for cold you can just keep going with appropriate dress.

Lastly, just to restate, the data in this chart are from unmotivated everyday commuting. What makes it fun and interesting is that I could have a lot of data points given it was the same route and distance each day for years. But I still consider that the OP was more interested in higher performance riding, like training or racing, plus there was no definition on bound on the ride duration, and this data is not like that, commuters generally put out moderate to high energy but not peak energy and some days it is more like a recovery ride. In any case, I am happy if you found it interesting as one input of many.

staehpj1

Oh, one thing I didn't mention was that when it is really cold I might get some exercised induced asthma. I can generally get past it with an easy long warmup. Also it is more likely when running than when riding for some reason. I still love getting out in the cold weather and miss the really cold weather and snow since moving south. Mountain biking is more forgiving of the cold weather and getting out trail running or on snowshoes or skis is a nice break from riding when that is not possible/desirable.

Jay Turberville

I think it is strong and interesting, but with data like this you need to be thinking of confounders. In this case, I wonder about darkness. I'm assuming the cold tracks with winter which means shorter daylight hours. People riding in darkness or limited light tend to ride a bit slower and more carefully. There may be other confounders I haven't considered. That said, it is nice to see so much objective data.

terrymorse 

"Extreme" cold for me on the bike has been around 32F. It may have slowed me down a little, probably because it felt uncomfortable.

"Extreme" heat for me has been up to 120F. That has slowed me down a lot, and sometimes it felt rather dangerous to continue. Weakness, fatigue, muscle cramps, body aches, nausea, headache, dizziness, vomiting.

Nope, there's no comparison. Extreme heat is way worse than cold.

gcasillo

I once rode at night when it was 15F. Due to proper clothing, I was comfortable and managed to stay out (though closer to home) for almost an hour. I had to turn for home when I found the water in my bottles an unpotable, icy slush. They were solid by the time I got inside.

Still, "extreme" being what it is, I'm slower and ride less in extreme heat or cold.

Wilbur Bud

Certainly one confounder I forgot to mention in the recent post is that at some point in winter, I put on the studded tires and they are slooooow compared to more typical road tires, probably a 10% hit, or 6 minutes. Where I live the studded tire season is likely end November to Mid-March if you are being careful, January and February if not. Sure on darkness, as a commuter, about two-thirds of my rides were in the dark.

Jay Turberville

I don't live in extreme cold. So I wouldn't have thought of that. So we have at least two confounders. If we had 20 or so more riders with nice data like yours, we could probably draw some general conclusions.

ofajen

I would concur that 32F is my boundary between “cold but enjoyable” and “why did I not go running indoors instead?”

OTOH, 120F is way, way beyond what I would consider allowable for cycling. About the most I will do is 95F and in that case I’m waiting until at least 4 pm, because at that point most of our trails are in shade.

So, basically, if I think it’s “extreme”, I’m not riding outside, and that’s below 32F or above 95F (possibly lower If humidity is higher.)

Otto