Recently someone mentioned on a website that his speech gets worse when it's cold. This has also been my experience, and it has led me to compare this with the fact that when it's cold, people naturally tend to protect themselves from the weather by tensing a number of muscles - we hunch our shoulders, tense our arms and keep them close to our bodies to keep warm, stiffen our necks etc.
If you believe, as I do, that stuttering is fundamentally the result of stress/tension-sensitive muscles of the vocal folds (also known as vocal cords) that "lock" when over-tensed, it makes sense that cold weather could make stuttering worse. Somewhat similar to us tensing our limbs in cold weather, the tendency of the muscles of our stress/tension-sensitive vocal folds to lock when overstressed may increase when temperatures are low. Alternatively, general body stress may be higher when it's cold, so increasing base-level stress which in turn decreases fluency margins. (For an explanation of "base-level stress/tension", "fluency margins" etc. check out THIS CHAPTER of Coping with Stuttering, my online book on stuttering.)
Conversely, one would expect that, in hot weather, stuttering may be less severe for many people who stutter. When it's hot, people generally tend to relax more, to "let go" and not hunch their shoulders and body muscles. Of course, one cannot generalise too much as stress / tension patterns differ individually and according to circumstances; but there may be an underlying trend here. Personally I have definitely found that my fluency is much better in summertime.
If cold weather impacts your fluency negatively, it could perhaps help in particular to keep the neck and throat warm with a scarf, and to generally try to keep as warm as possible. If this helps, please let me know by adding a comment below this post.
As mentioned, stress patterns in people differ, so that some people get more stressed than others due to temperature, but even so it is interesting that, in a previous survey of mine, more people who stutter were negatively impacted by cold weather (9 votes) compared to those who stuttered more in hot weather (3 votes). Certainly hot weather can also stress people just like the cold can - that's where the expression "hot and bothered" comes from! Extremes of temperature are probably stressing, irrespective of whether cold or hot. It would be interesting to experiment with PWS in controlled temperatures to see how we react to temperature. Excuse me while I prepare my cold storage room ... :-)
Update December 2012: I asked this same question to the professionals at the 2012 ISAD (International Stuttering Awareness Day) Online Conference. My question was as follows:
"Dear panel, I wondered if any research is available on the relationship between stuttering and temperature? For instance, do some people tend to stutter more when the weather is cold? In a poll on my blog recently, 9 people said that their speech was worse in cold conditions, whereas 3 said that their speech was better when it's cold. 12 said that temperature didn't make any difference, and 15 said that they hadn't noticed any difference. Personally I find that my speech is markedly better when the temperature is nice and warm, but markedly worse in cold temperatures. I would ascribe this to muscle tension and stress - when it's cold, some people maybe tend to tense their muscles to ward off the cold, whereas when the weather is nice, people tend to be more relaxed. I thought this was rather interesting, but has this been researched before?"
I received one reply from Ken St Louis:
"Hello Peter, Interesting question. I'm quite sure I've never seen a study on the relationship between outside temperature and stuttering. Of course if one did, it would require lots of controls, e.g., humidity, upper respiratory infections, air conditioning, actual temperature differences in different seasons, etc. It looks like your little survey suggests that temperature is probably not a large predictor of stuttering: 23% worse, 8% better, and 69% no difference. That said, you might have a significant difference with a Chi Square which clearly would PROVE that cold weather is bad for people who stutter. JUST JOKING
My response: I'm still not convinced - I suspect that cold DOES have an impact on the fluency of many (not all) people who stutter, and that the muscle tension caused by cold temperatures can have an effect on either the vocal-cord muscles, thereby directly impacting speech, or on general muscle tension (= general stress levels), thereby indirectly impacting speech, or both. Of course not everyone's speech will be impacted by cold - people have different stress patterns and will respond differently to cold.
29 December 2012: I have created a new poll on this issue to get a larger sample. Kindly take part! I would love to get your response. Many thanks in advance! This, of course, is not a "scientific" survey but will hopefully create interest so that the real experts will take it further. Here is the poll: