Individual Differences in Sensitivity to Daily Meteorological Fluctuations Among Collegiate Baseball Players: A Repeated-Measures Observational Study

BackgroundMeteorological factors such as barometric pressure, humidity, and temperature have been linked to weather-related symptoms in the general population, yet little is known about their influence on athletes daily well-being and performance. Individual variability in weather sensitivity has been reported in biometeorology research, suggesting that only certain individuals exhibit pronounced physiological responses to environmental fluctuations. However, no studies have examined within-person associations between multiple meteorological factors and daily condition or performance in competitive athletes. MethodsCollegiate baseball players were monitored over 10 randomly selected days during July-August 2025. Subjective condition and performance were assessed daily using a 3-point Likert scale (1 = poor, 2 = normal, 3 = good). Barometric pressure, humidity, and temperature were recorded hourly and summarized for each day using mean values, day-to-day changes, daily ranges, and rapid fluctuation indices. For each player, multivariable linear regression models were constructed to examine within-person associations between the three meteorological variables and daily condition or performance. Model fit (R2), regression coefficients ({beta}), and dominant meteorological factors were extracted. ResultsEighty players were included in the condition model and eighty-six in the performance model. High weather sensitivity (R2 [≥] 0.60) was observed in 22.5% of players for condition and 14.0% for performance, whereas low sensitivity (R2 [≤] 0.20) was found in 26.3% and 16.3%, respectively. Temperature was the dominant explanatory factor in more than 80% of players, although subsets showed dominance of barometric pressure or humidity. Directionality varied across individuals: decreases in barometric pressure were associated with worsening conditions in 62.5% of players but improvement in 37.5%; similar bidirectional patterns were observed for humidity and temperature. ConclusionDaily meteorological fluctuations explain a meaningful proportion of within-person variation in condition and performance for a subset of collegiate baseball players. The substantial individual variability and diverse directional responses highlight weather sensitivity as a personalized characteristic rather than a uniform effect. These findings suggest that meteorological factors may represent a relevant contextual variable for daily readiness monitoring in susceptible athletes.