Seasonal variation in cardiometabolic health has been recognized for decades, with winter months consistently associated with higher blood pressure, impaired glycemic control, and increased cardiovascular events. A robust body of literature shows that systolic blood pressure (SBP) rises in colder months by up to 10 mmHg, driven by environmental, behavioral, and metabolic factors. Seminal studies such as Cuspidi et al. (Hypertension, 2012) and Brook et al. (JASH, 2011) outline predictable winter elevations across populations and climates, emphasizing that seasonality is not noise, it is physiology.
Consequentially, winter months are associated with greater cardiovascular events. Using data from 300,000 cardiovascular deaths in the Canadian Mortality Database, Sheth et al. reported that mortality from acute myocardial infarction and stroke was 19% and 20% higher in January than in September, respectively. These results were consistent with a decades-long community based study in Minnesota which found a 17% increase in sudden cardiac death in winter months compared with summer.
The holiday season amplifies these effects. Reduced physical activity, higher sodium intake, increased caloric and alcohol consumption, emotional stress, circadian disruption, and diminished sunlight exposure create a convergence of factors that transiently elevate blood pressure. High–glycemic load meals, common during holiday periods, provoke sharp insulin spikes, leading to renal sodium retention, increased blood volume, extracellular fluid shifts, and weight gain, all of which directly raise SBP. When layered onto the intrinsic vasoconstrictive effects of colder temperatures, the winter environment becomes a perfect storm for hemodynamic strain.
Traditional office-based blood pressure monitoring, often occurring only once or twice per year, cannot capture these patterns. In contrast, continuous Remote Patient Monitoring (RPM) provides a high-fidelity view of real-world physiology, revealing the interaction between lifestyle, environment, and biology with a precision never before available in population-scale hypertension management. Similarly, research on seasonal blood pressure change often relies on medical records data. RPM-derived data enables the most detailed assessment of these changes.
Leveraging one of the largest RPM hypertension datasets in the United States, HealthSnap analyzed over 25 million de-identified blood pressure measurements from 2023 to 2025. The results offer the clearest real-world demonstration to date of how season, geography, age, and time on program shape blood pressure trajectories.
Figure: Change in SBP Across Patient Months by Quarter Cohort
The figure above shows a strikingly consistent pattern across all quarterly enrollment cohorts. Regardless of when patients joined the program, SBP falls rapidly during the first 3–6 months of RPM participation, reflecting accelerated clinical optimization, tightened medication titration, lifestyle adjustments, and enhanced engagement. After this period, SBP stabilizes at approximately 10–15 mmHg below baseline, a durable and clinically meaningful improvement observed across tens of thousands of patients (p < 0.0001).
Layered atop this downward shift of ~1-2 mmHg per year is a gentle seasonal curve: a 3–5 mmHg oscillation that reflects the natural annual rhythm of blood pressure. Patients enrolling in Q4 or Q1—the colder, holiday-heavy months, begin with slightly elevated SBP, while Q2 and Q3 enrollees start closer to the annual summer trough. Physiologically, this distinction makes sense: cold temperatures, holiday diet patterns, circadian disruption, and reduced physical activity all increase sympathetic tone and vascular resistance, whereas summer conditions promote lower vascular tone and more movement.
Even so, the overarching pattern remains unmistakable: RPM drives a sustained, meaningful reduction in blood pressure, with the winter rise and summer dip simply superimposed on a healthier long-term trajectory.
Figure: Seasonal Crests and Troughs Across 2023–2025
The figure above illustrates the clearest multi-year visualization of seasonal blood pressure behavior. When we align thousands of Q1 enrollees from 2023, 2024, and 2025 by patient month, a smooth, repeating annual rhythm emerges.
Crucially, these curves persist even after removing each patient’s first six months of RPM, ensuring we are observing true physiology rather than the onboarding effect. RPM lowers the baseline SBP level, but the seasonal wave remains fully intact, simply oscillating around a lower, healthier set point.
With millions of data points collected daily across years, this dataset offers some of the strongest real-world confirmation of seasonal SBP behavior ever reported—far more precise than traditional clinic-based epidemiology, which relied largely on infrequent annual office visits.
The takeaway: blood pressure is seasonal, and this figure reveals that rhythm with unprecedented clarity.
Figure: Calendar-Month BP Fluctuations (2023–2025)
This figure transitions from patient-month trajectories to true calendar-month environmental seasonality. To isolate seasonal effects, the analysis was limited to patients transmitting at least twice per month and excluded each patient’s first six months on program.
Across three consecutive years, the pattern is highly reproducible:
Even when examining change-from-baseline curves, seasonality remains fully visible, demonstrating that this pattern is not an artifact of treatment, but a stable, biology-driven phenomenon.
These findings reinforce a fundamental point: environmental seasonality imprints itself on blood pressure in a predictable, measurable way, and RPM uniquely makes this visible.
Figure: Regional SBP Differences Across Calendar Months
The regional comparison figure highlights a subtle but informative trend. In some years, patients in southern states (red) begin January with slightly higher SBP than northern patients (blue). However, this early-year difference gradually narrows, and by July the two curves become nearly indistinguishable. For the next 12 months, northern and southern patterns track almost identically with only minimal variation.
This suggests that while climate may contribute modestly to early-year differences, behavioral factors such as holiday diet patterns, reduced activity, alcohol intake, sleep changes, and winter stress likely play an equally important role, affecting patients nationwide regardless of latitude.
The most consistent signal is the shared underlying rhythm: SBP rises every winter and falls every summer, independent of geography.
Figure: Seasonal Amplitude by Age Group
The table above shows that seasonal SBP fluctuations become progressively larger with age, even under active monitoring:
This represents a 30–40% increase in winter-to-summer variation across older decades.
Mechanistic contributors include:
These findings underscore the importance of year-round monitoring, especially for older adults, where even modest winter increases in SBP can meaningfully elevate cardiovascular event risk.
Taken together, longitudinal curves, seasonal crests and troughs, calendar-month analyses, and regional and age-stratified comparisons, one conclusion is clear:
Seasonality is real, physiologic, and clinically significant.
Office-based care almost never captures this. A patient may appear perfectly controlled during a summer clinic visit yet drift into meaningful hypertension by winter. Conversely, a winter reading may falsely imply poor control, leading to overtreatment if the clinician is unaware of the natural seasonal rise.
Remote Patient Monitoring resolves this blind spot.
Continuous data:
The rhythm has always existed, RPM simply makes it visible.
Seasonal increases in blood pressure are not benign. Large epidemiologic studies consistently show that winter months bring higher cardiovascular event rates, including a 10–20% rise in myocardial infarction and a meaningful increase in stroke hospitalizations. Critically, even a small 5 mmHg increase in systolic blood pressure raises the risk of major cardiovascular events by roughly 10%. This means that the 3–5 mmHg winter rise observed in HealthSnap’s 25-million-measurement dataset represents a real, quantifiable contributor to seasonal cardiovascular risk. The impact is greatest among older adults, northern-latitude populations, and individuals with insulin resistance or metabolic disease. For clinicians and health systems, the implication is clear: RPM enables earlier detection, earlier action, and reduced cardiovascular risk, especially during the high-risk winter months.
Across more than 25 million real-world measurements, HealthSnap’s national RPM dataset demonstrates:
Together, these findings underscore a fundamental insight:
Blood pressure is not static, and our care models cannot be either.
Continuous remote monitoring reveals the full physiologic rhythm of blood pressure, allowing clinicians to anticipate seasonal risk, individualize therapy, and intervene earlier. In a healthcare landscape increasingly focused on precision and prevention, recognizing and responding to these seasonal dynamics is essential for improving outcomes and saving lives.
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