DiscussionThe aim of the study was

Discussion
The aim of the study was to investigate the effect of daily
weather changes on people’s mood. It was expected that individual
differences in sensitivity to weather changes exist. The results of
the current study showed no significant main effects of daily
weather on positive affect. This result is consistent with findings
by Keller et al. (2005) and Watson (2000), who also did not find
effects of weather on overall mood valence. Going against commonly
held conceptions (Watson, 2000), it is interesting to note
that none of the six weather parameters had any significant main
effects on positive mood. Accordingly, the idea that pleasant
weather increases people’s positive mood in general is not supported
by the findings of this study, although the finding of
significant between-person variance suggests that such a link may
still exist for some individuals (while simultaneously a reverse
effect holds for others).
Significant main effects of temperature, wind power, and sunlight
on negative affect were found. The difference between the
multivariate and univariate results showed that it was very informative
to include different weather variables to identify the unique
effect of each variable. The multivariate analysis showed unique
effects of temperature, wind power, and sunlight, whereas the effects
of temperature and sunlight were not visible in the univariate analyses
because of confounds. Because univariate analyses do not control
for other variables, positive and negative effects might cancel each
other out.
Sunlight was found to have a significant main effect on tiredness
and mediated the effect of precipitation and air pressure on tiredness.
Vitamin D3, which is produced in skin exposed to the
hormone of sunlight, has been found to change serotonin levels in
the brain, which could account for changes in mood (Lansdowne
& Provost, 1998). Therefore, lower levels of vitamin D3 could be
responsible for increases in negative affect and tiredness.
As indicated by the relatively small regression weights (|.071|),
weather fluctuations accounted for very little variance in people’s
day-to-day mood. This result may be unexpected given the
existence of commonly held conceptions that weather exerts a
strong influence on mood (Watson, 2000), though it replicates
findings by Watson (2000) and Keller et al. (2005), who also
failed to report main effects. A number of factors may explain
the discrepancy between empirical results and widely held
beliefs (see also Watson, 2000). For example, it may be that
these beliefs are a reflection of our historical (and possibly
culturally transmitted) past, when people were much more
dependent on weather-related phenomena (e.g., for shelter and
food). It may also be that the discrepancy is because of a small
number of extreme cases (e.g., individuals with SAD) who
indeed report a strong association between weather and mood.
Such cases may leave a very vivid impression on others, but the
existence of significant between-person variance against the
background of a null effect in the general population suggests
that these extreme cases are offset by individuals with strikingly
different weather dependencies (e.g., people who become sadder
during summers instead of winters).
The random effects analyses indicated that the effects of
weather on positive affect, negative affect, and tiredness varied
significantly across individuals. This was especially true for the
effect of photoperiod. Even though the within-subject range of this
variable (M  0.83, SD  0.73) was vastly reduced when compared
to the range of the amount of hours with unobstructed
sunlight (M  7.56, SD  4.64), the random slope variance
between persons was between 9 (positive affect) and 23 (tiredness)
times greater in the former when compared to the latter. On
average, the random effect for photoperiod was no less than 21
times greater than the average random effect of the other five
weather variables, indicating that individual differences in reactions
to changes in photoperiod are much more extreme than
reactions to day-to-day weather fluctuations. This means that
whereas some individuals may react to the shortening of daylight
time with a relatively strong darkening of their mood, the emotions
of other individuals may actually improve equally strongly as a
result of this seasonal change. The former individuals may be the
ones who fall prey to SAD during the dark season, though more
research is needed to substantiate this conclusion.
Inclusion of the Five Factor Model personality traits, gender and
age, did not reveal more moderation effects of the person-level
variables than expected by chance. In other words, people seem to
differ in the effects of weather on mood in a way that cannot be
explained by the Five Factor Model personality traits, age, or
gender. This might suggest that weather sensitivity is an individual
difference variable by itself. Research on diurnal types (e.g.,
Jackson & Gerard, 1996) and seasonality (Reid, Towell, & Golding,
2000) also found individual differences that were independent
to other personality traits. The findings of the present study suggest
that people can also differ in weather sensitivity, independent from
other personality traits.
The current study also investigated the moderating effect of
season on the association between weather and mood in an attempt
to replicate the finding by Keller et al. (2005) that weather fluctuations
have an especially strong effect in spring. Consistent with
this, we found that wind power had a more negative effect on
positive mood during spring and summer. This might be because
of the fact that people spend more of their leisure time outside
during these periods, so experiencing strong winds represents more
of a hassle, though this conclusion is highly speculative and needs
to be backed up by future research.
Strengths. Usually, causal effects can only be identified in
experimental designs. However, weather is an external variable
that cannot be influenced by individuals’ mood or any other third
variable. Although our naturalistic design did not allow us to
establish causality in the strict (experimental) sense, we believe
that are findings are highly consistent with a causal model that
flows from weather to mood (although we acknowledge that our
results remain silent regarding the processes that mediate associations
between weather and mood, such as physiological processes
or daily activities). Furthermore, the data collection for the current
study ran over an 18-month period, spanning all seasons, which
provided a robust examination of the association between weather

Hasil (Bahasa Indonesia) 1:

DiskusiTujuan penelitian ini menyelidiki efek harianperubahan cuaca suasana hati rakyat. Diharapkan bahwa individuada perbedaan dalam kepekaan terhadap perubahan cuaca. HasilPenelitian ini menunjukkan efek utama signifikan sehari-hariCuaca di pengaruh positif. Hasil ini konsisten dengan temuandengan Keller et al. (2005) dan Watson (2000), yang juga tidak menemukanEfek cuaca pada keseluruhan suasana valence. Akan melawan umumnyadiadakan konsepsi (Watson, 2000), hal ini menarik untuk dicatatbahwa tidak ada enam parameter cuaca telah utama setiap signifikanefek pada suasana hati yang positif. Dengan demikian, gagasan yang menyenangkanCuaca meningkat orang positif MOODs secara umum tidak didukungoleh temuan-temuan dari studi ini, meskipun temuanvarians signifikan antara orang menunjukkan bahwa link tersebut dapatmasih ada untuk beberapa individu (sementara secara bersamaan reverseEfek memegang untuk orang lain).Efek utama yang signifikan suhu, tenaga angin dan sinar mataharipada negatif mempengaruhi ditemukan. Perbedaan antaramultivarian dan univariat hasil menunjukkan bahwa itu sangat informatifuntuk menyertakan variabel-variabel cuaca yang berbeda untuk mengidentifikasi yang unikefek dari setiap variabel. Analisis multivarian menunjukkan unikEfek suhu, angin kekuasaan, dan sinar matahari, sedangkan efeksuhu dan sinar matahari yang tidak terlihat dalam analisis univariatkarena mengacaubalaukan antara. Karena analisis univariat tidak mengontrolfor other variables, positive and negative effects might cancel eachother out.Sunlight was found to have a significant main effect on tirednessand mediated the effect of precipitation and air pressure on tiredness.Vitamin D3, which is produced in skin exposed to thehormone of sunlight, has been found to change serotonin levels inthe brain, which could account for changes in mood (Lansdowne& Provost, 1998). Therefore, lower levels of vitamin D3 could beresponsible for increases in negative affect and tiredness.As indicated by the relatively small regression weights (|.071|),weather fluctuations accounted for very little variance in people’sday-to-day mood. This result may be unexpected given theexistence of commonly held conceptions that weather exerts astrong influence on mood (Watson, 2000), though it replicatesfindings by Watson (2000) and Keller et al. (2005), who alsofailed to report main effects. A number of factors may explainthe discrepancy between empirical results and widely heldbeliefs (see also Watson, 2000). For example, it may be thatthese beliefs are a reflection of our historical (and possiblyculturally transmitted) past, when people were much moredependent on weather-related phenomena (e.g., for shelter andfood). It may also be that the discrepancy is because of a smallnumber of extreme cases (e.g., individuals with SAD) whoindeed report a strong association between weather and mood.Kasus tersebut dapat meninggalkan kesan yang sangat jelas pada orang lain, tetapikeberadaan varians signifikan antara orang melawanmenunjukkan latar belakang efek null di populasi umumbahwa kasus-kasus ekstrim ini adalah diimbangi oleh individu dengan mencolokdependensi cuaca yang berbeda (misalnya, orang-orang yang menjadi sedihselama musim panas bukan musim dingin).Acak efek analisis menunjukkan bahwa efekCuaca di pengaruh positif, negatif mempengaruhi dan kelelahan bervariasisecara signifikan di seluruh individu. Ini adalah terutama berlaku untukEfek photoperiod. Meskipun kisaran dalam subjek inivariabel (M 0.83, SD 0,73) jauh berkurang dibandingkandengan jangkauan jumlah jam dengan terhalangsinar matahari (7,56 M, SD 4,64), varians lereng acakantara orang adalah antara 9 (pengaruh positif) dan 23 (kelelahan)kali lebih besar di bekas bila dibandingkan dengan yang kedua. Padarata-rata, efek acak untuk photoperiod adalah tidak kurang dari 21kali lebih besar daripada rata-rata acak efek lima lainnyaCuaca variabel, menunjukkan bahwa perbedaan dalam reaksiperubahan dalam photoperiod lebih ekstrem daripadareaksi terhadap fluktuasi cuaca sehari-hari. Ini berarti bahwasedangkan beberapa individu dapat bereaksi memperpendek panaskali dengan gelap relatif kuat suasana hati mereka, emosiorang lain mungkin benar-benar meningkatkan sama kuat sebagaihasil dari perubahan musiman ini. Mantan individu mungkinorang-orang yang jatuh mangsa ke SAD selama musim gelap, meskipun lebihPenelitian sangat diperlukan untuk mendukung kesimpulan ini.Dimasukkannya ciri-ciri kepribadian lima Model faktor, jenis kelamin danusia, tidak mengungkapkan lebih banyak efek moderasi tingkat orangvariabel dari yang diharapkan secara kebetulan. Dengan kata lain, orang-orang tampaknyaberbeda dalam efek cuaca pada suasana dengan cara yang tidak dapatdijelaskan oleh ciri-ciri kepribadian lima Model faktor, usia, ataujenis kelamin. Ini mungkin menunjukkan bahwa cuaca sensitivitas individuperbedaan variabel dengan sendirinya. Penelitian pada diurnal jenis (misalnya,Jackson & Gerard, 1996) dan musiman (Reid, Towell, & Golding,2000) juga menemukan perbedaan individual yang independenuntuk Ciri-ciri kepribadian lainnya. Temuan dari penelitian ini menunjukkanbahwa orang dapat juga berbeda dalam cuaca kepekaan, independen dariCiri-ciri kepribadian lainnya.Penelitian ini juga menyelidiki efek moderatmusim pada Asosiasi antara cuaca dan suasana hati dalam upayauntuk mereplikasi temuan oleh Keller et al. (2005) yang cuaca fluktuasimemiliki efek terutama kuat pada musim semi. Konsisten denganini, kita menemukan bahwa tenaga angin memiliki efek lebih negatifmood positif selama musim semi dan musim panas. Ini mungkin karenafakta bahwa orang-orang menghabiskan lebih banyak waktu luang mereka di luarselama periode ini, jadi mengalami angin yang kuat mewakili lebihof a hassle, though this conclusion is highly speculative and needsto be backed up by future research.Strengths. Usually, causal effects can only be identified inexperimental designs. However, weather is an external variablethat cannot be influenced by individuals’ mood or any other thirdvariable. Although our naturalistic design did not allow us toestablish causality in the strict (experimental) sense, we believethat are findings are highly consistent with a causal model thatflows from weather to mood (although we acknowledge that ourresults remain silent regarding the processes that mediate associationsbetween weather and mood, such as physiological processesor daily activities). Furthermore, the data collection for the currentstudy ran over an 18-month period, spanning all seasons, whichprovided a robust examination of the association between weather