Debunking the Myth: Does Cold Weather Really Cause Colds?
As winter approaches, you often hear reminders to bundle up to avoid catching a cold, leading many to wonder: Does cold weather really cause colds? It’s a query that has floated through frosty air for generations. Let’s unravel this chilly myth and find out what truly influences the risk of developing a cold.
Introduction
Despite what your grandmother may have insisted, the link between cold weather and catching a cold virus is one of the most enduring health myths. In this blog post, we’ll dive into the facts behind this misconception. Why do more people fall ill during the colder months? If it’s not the low temperatures directly causing the illness, what is? Understanding the real reasons can help you better protect yourself and your family during the cold season.
Delving into the Myth
The common cold, primarily caused by rhinoviruses, strikes millions globally each year, leading to a mountain of tissues and missed days of work or school. The pervasive belief that cold weather is the culprit behind these sniffles and coughs is based more on correlation than causation. Indeed, cold and flu season does coincide with colder months, but direct causation by cold weather isn’t scientifically upheld.
Scientific Insights: The Real Culprits
1. Indoor Crowding:
During colder weather, people tend to stay indoors more often. This proximity in closed environments like homes, schools, and offices facilitates easier transmission of viruses. Viruses that cause colds spread more readily when individuals are in close contact with one another, explaining the uptick in respiratory illnesses during the winter.
2. Humidity and Heating:
Low humidity levels, common during winter due to indoor heating, can dry out the nasal passages and reduce the respiratory system’s ability to filter out viruses. Moreover, dry air allows the virus particles to remain airborne longer, increasing the likelihood of inhalation and infection.
3. Diminished Sun Exposure:
Shorter days and less sunlight lead to reduced levels of vitamin D and perhaps even melatonin, both important for immune system regulation. A compromised immune response can increase susceptibility to infections, including the common cold.
FAQs About Cold Weather and Colds
Q: Can you catch a cold from going outside with wet hair in the cold? A: This is another widespread myth. Going outside with wet hair does not cause you to catch a cold. Colds are caused by viruses, not cold temperature or wet hair. However, being cold and wet can make you uncomfortable, possibly stressing your immune system which might make you more susceptible to an existing virus.
Q: Should I dress warmly to avoid catching a cold? A: While dressing warmly won’t directly prevent a cold, it can keep you comfortable and potentially stave off the stress that might weaken your immune defenses. In essence, it’s beneficial to dress appropriately for the weather for overall comfort and health.
Q: Is the flu shot effective in preventing colds during winter? A: The flu shot is specifically designed to protect against influenza and not the common cold. However, since symptoms of the flu can sometimes resemble those of a cold, getting vaccinated can help you avoid some wintertime illnesses and improve your overall resilience.
Preventative Measures
Understanding that the cold weather itself isn’t the root cause of colds, you can take practical steps to reduce your risk:
- Hygiene: Regular handwashing remains one of the most effective ways to prevent the spread of viruses. Also, avoid touching your face, particularly the eyes, nose, and mouth.
- Humidifiers: Using a humidifier in your home can help maintain optimal humidity, potentially reducing the survival of viruses.
- Healthy Lifestyle: Maintain a balanced diet rich in fruits and vegetables, get regular physical activity, and ensure you get enough sleep, all of which bolster your immune system.
- Social Distancing: During peak cold and flu season, it can be wise to avoid overly crowded places when possible.
Conclusion
Debunking the myth: Does cold weather really cause colds? No, it doesn’t—not directly, at least. While colder weather correlates with an increase in colds, it’s mainly due to factors associated with the winter season, such as indoor crowding and lower humidity levels. By taking preventive actions and maintaining a healthy lifestyle, you can help fend off the common cold, regardless of the weather outside! Stay informed, stay warm, and stay well this winter season.
What the evidence actually says
The claim being checked: “Cold weather causes colds”
The short answer
Partly true, and the standard debunking is as wrong as the myth. A virus still has to reach you, and cold air does not manufacture one. But when researchers chilled people’s feet in a randomised trial, more of them came down with cold symptoms over the following days, and there is now a mechanism measured in human nasal tissue that explains how that could happen.
What is true in it
Three separate lines of evidence point the same way, which is more than most myths manage. Johnson and Eccles (2005) randomised 180 healthy people to a foot chill or a control procedure; over the next four to five days, 13 of 90 chilled subjects reported a cold against 5 of 90 controls (P = .047). In a Finnish population study following 892 conscripts through 643 diagnosed infections, every 1 degree Celsius drop in outdoor temperature raised the estimated risk of upper respiratory infection by 4.3 percent, and temperature fell measurably across the three and fourteen days before onset (Mäkinen et al., 2009). A 2025 systematic review that screened 5,789 articles and kept 21 found low temperature associated with more respiratory infection in 11 of the 19 studies that tested it (Hyrkäs-Palmu et al., 2025).
Where it breaks
The leap is skipping the virus. Cold air does not generate a pathogen, and no amount of chilling produces an infection in a room where the virus is absent. What the evidence supports is narrower and less dramatic than what people mean when they say it: cold appears to lower your nose’s defence against a virus you were going to meet anyway.
The part most debunkings leave out
Here is the part nobody separates out. “Cold” is at least four different exposures, and they do not behave alike. Eccles and Wilkinson (2015) pulled them apart: breathing cold air, chilling the body surface, swallowing cold food and drink, and whole-body hypothermia. They found evidence supporting the first two, and none at all for the other two. So there is nothing behind the idea that ice cream or a cold drink gives you a cold, and nothing behind hypothermia doing it either. Chilled skin and cold air in the nose are a genuinely different question, and the honest answer there is that the field is still arguing.
The mechanism has also moved recently, and moved in a direction that matters. The paper everyone cites, Foxman et al. (2015), was done in mouse airway cells, which is a long way from a person. Huang et al. (2023) repeated the question in human nasal epithelial cells and in fresh human nasal tissue taken at surgery, and found that cold exposure cut the nose’s antiviral response: fewer protective extracellular vesicles released, less microRNA packed into them, weaker binding to virus. That is no longer a mouse-shaped argument. It is still a mechanism rather than an outcome, and a mechanism can explain how something might happen without establishing that it does.
How this was researched
The question I actually searched
In people, does exposure to cold, whether ambient cold weather or deliberate chilling of the body, increase how often or how badly they get a common cold or other upper respiratory infection, compared with people not so exposed?
Searches run, verbatim
PubMed and MEDLINE, through the NCBI E-utilities interface · searched 21 September 2026 · no date limit on experimental and landmark work, 2015 onward for the epidemiology, because that is where the recent studies sit
((cold exposure[tiab]) OR (chilling[tiab]) OR (cold stress[tiab]) OR (cold water immersion[tiab])) AND ((common cold[tiab]) OR (upper respiratory tract infection[tiab]) OR (rhinovirus[tiab]))
→ 27 records
((ambient temperature[tiab]) OR (cold weather[tiab]) OR (seasonality[tiab]) OR (winter[tiab])) AND ((respiratory tract infection*[tiab]) OR (common cold[tiab]) OR (rhinovirus[tiab])) AND (incidence[tiab] OR risk[tiab] OR association[tiab])
→ 60 records
(temperature[tiab]) AND ((innate immun*[tiab]) OR (interferon[tiab]) OR (mucociliary[tiab]) OR (nasal epitheli*[tiab])) AND ((rhinovirus[tiab]) OR (respiratory virus*[tiab]))
→ 22 records
((cold exposure[tiab]) OR (temperature[tiab]) OR (cold weather[tiab])) AND ((common cold[tiab]) OR (upper respiratory[tiab])) AND ((systematic review[pt]) OR (meta-analysis[pt]) OR (systematic review[tiab]) OR (meta-analysis[tiab]))
→ 15 records
Screening
- 512records matched
- 124titles screened
- 11read in full
- 6used here
The four strands matched 512 records between them. One of them, the ambient-temperature epidemiology, returned 448 on its own, so I screened the sixty most relevant from that strand and every record from the other three. That is a real limit on this brief and not a formality: a relevant study sitting sixty-first in that strand would never have reached me.
What got in
- Human subjects, or human tissue where the paper is being used only for mechanism.
- The exposure is cold in some measurable form: air temperature, body or extremity chilling, or tissue temperature.
- The outcome is a respiratory infection or its symptoms, not a surrogate such as a cytokine level standing in for illness.
- A design that can answer the question being asked of it, with trials outranking cohorts and cohorts outranking ecological studies.
- Peer reviewed, retrievable, and not retracted.
What got left out, and why
- Collier et al. (2021) on habitual cold-water swimmers, which likely points the other way and is the single most interesting record the search returned. It is published as a letter, and the abstract I could retrieve stops before the results. I will not describe findings I have not read, so it is named here and left out of the reasoning.
- Boonarkart et al. (2017), titled as showing that cold impairs interferon-induced antiviral defence. No abstract body was retrievable, so the title alone is not enough to cite it for anything.
- Shaw Stewart (2016) in Medical Hypotheses, which is a hypothesis paper by design and is not evidence about people.
- Everything the strings dragged in off-target: cold-water immersion and mental health, cold weather injuries in the armed forces, cold tolerance in crops, echinacea trials, and studies of cold exposure used for weight control.
- Studies whose outcome was a laboratory marker rather than an actual infection.
The evidence, ranked by what the design can prove
| Study | Design | Tier | n | What it found | What it cannot say |
|---|---|---|---|---|---|
| Johnson & Eccles (2005) | Randomised controlled trial, foot chilling | Tier 2 | 180 | 13 of 90 chilled subjects reported a cold within 4 to 5 days, against 5 of 90 controls (P = .047). No acute change in symptom scores at the time of chilling. | Symptoms were self-reported with no virological confirmation, and subjects knew whether their feet had been in cold water. The people who developed colds also reported more colds per year, so chilling may be unmasking rather than causing. |
| Hyrkäs-Palmu et al. (2025) | Systematic review of observational studies | Tier 3 | 21 studies from 5,789 screened | Low temperature was associated with increased respiratory infection in 11 of 19 studies that examined it. Population density was associated in 14 of 15. | Every included study was register-based and ecological, so it describes populations rather than people, and it cannot separate cold from the crowding and indoor time that arrive with it. |
| Mäkinen et al. (2009) | Prospective population study | Tier 3 | 892 people, 643 infections | Each 1 degree Celsius fall in temperature raised estimated upper respiratory infection risk by 4.3 percent (P < .0001) and common cold risk by 2.1 percent (P = .004). Temperature declined across the 3 and 14 days before onset. | Observational, in military conscripts in a northern climate, so confounding by indoor crowding and by the season itself cannot be excluded. |
| Eccles & Wilkinson (2015) | Narrative review separating four kinds of cold exposure | Tier 5 | n/a | Evidence supports a relationship for breathing cold air and for acute chilling of the body surface. No evidence was found for cold food and drink, or for hypothermia. | Narrative rather than systematic, with no stated search or selection rules, so it is a well-informed synthesis rather than a reproducible one. |
| Huang et al. (2023) | Mechanism in human nasal cells and fresh human nasal tissue | Tier 5 | Human cells and surgical specimens | Cold exposure reduced secretion of antiviral extracellular vesicles from nasal epithelium, reduced the microRNA packed into them, and weakened their binding to virus. | Mechanism, not outcome. It shows a plausible route from cold nose to weaker defence. It does not show that people exposed to cold get more infections. |
| Foxman et al. (2015) | Mechanism in mouse airway cells | Tier 5 | Mouse cells | Interferon-driven antiviral gene expression was markedly stronger at 37 degrees Celsius than at the 33 to 35 degrees found in the nasal cavity, giving rhinovirus more room to replicate when cool. | Mouse cells. Superseded for this purpose by the human tissue work, and retained only because it is the study most often quoted in popular coverage. |
Tier 1 is a meta-analysis or systematic review of randomised trials. Tier 2 is a single randomised trial. Tier 3 is a prospective cohort or a systematic review of observational studies. Tier 4 is case-control, cross-sectional or ecological. Tier 5 is mechanism or narrative review: cell, tissue or animal work, a case report, or an expert synthesis, which can explain how something might happen but never establishes that it does happen in people. The full hierarchy is in the method.
How certain this is, and why
What would change this
A randomised trial with virologically confirmed infection instead of self-reported symptoms, and enough events to pull the interval away from the line, would settle this in either direction. So would a proper prospective study of habitual cold-water swimmers, who may well run the other way. Collier et al. (2021) set out to measure exactly that group, and I could not retrieve their results, so I have left them out of the reasoning rather than guess. If their finding is what the swimming community claims, the picture here gets more interesting rather than less.
References
- Johnson, C., & Eccles, R. (2005). Acute cooling of the feet and the onset of common cold symptoms. Family Practice, 22(6), 608-613. https://doi.org/10.1093/fampra/cmi072 (PMID 16286463)
- Hyrkäs-Palmu, H., Hugg, T. T., Jaakkola, M. S., & Jaakkola, J. J. K. (2025). The influence of weather and urban environment characteristics on upper respiratory tract infections: A systematic review. Frontiers in Public Health, 13, 1487125. https://doi.org/10.3389/fpubh.2025.1487125 (PMID 39995623)
- Mäkinen, T. M., Juvonen, R., Jokelainen, J., Harju, T. H., Peitso, A., Bloigu, A., Silvennoinen-Kassinen, S., Leinonen, M., & Hassi, J. (2009). Cold temperature and low humidity are associated with increased occurrence of respiratory tract infections. Respiratory Medicine, 103(3), 456-462. https://doi.org/10.1016/j.rmed.2008.09.011 (PMID 18977127)
- Eccles, R., & Wilkinson, J. E. (2015). Exposure to cold and acute upper respiratory tract infection. Rhinology, 53(2), 99-106. https://doi.org/10.4193/Rhino14.239 (PMID 26030031)
- Huang, D., Taha, M. S., Nocera, A. L., Workman, A. D., Amiji, M. M., & Bleier, B. S. (2023). Cold exposure impairs extracellular vesicle swarm-mediated nasal antiviral immunity. Journal of Allergy and Clinical Immunology, 151(2), 509-525.e8. https://doi.org/10.1016/j.jaci.2022.09.037 (PMID 36494212)
- Foxman, E. F., Storer, J. A., Fitzgerald, M. E., Wasik, B. R., Hou, L., Zhao, H., Turner, P. E., Pyle, A. M., & Iwasaki, A. (2015). Temperature-dependent innate defense against the common cold virus limits viral replication at warm temperature in mouse airway cells. Proceedings of the National Academy of Sciences, 112(3), 827-832. https://doi.org/10.1073/pnas.1411030112 (PMID 25561542)
- Named but not used: Collier, N., Lomax, M., Harper, M., Tipton, M., & Massey, H. (2021). Habitual cold-water swimming and upper respiratory tract infection. Rhinology, 59(5), 485-487. https://doi.org/10.4193/Rhin21.068 (PMID 34428265). Results were not retrievable from the published abstract.
Searched, screened, read and written by Yaa Boakye, MBA, RDN, LDN, CPT · every paper cited was retrieved and read, never cited from memory · reviewed 21 Sept 2026 · next review due Sept 2027 · the protocol behind this · all investigations
