1 Some people hate the change in routine
Many people find it uncomfortable to change their daily routine in summer. In winter, everything is planned and predictable, but in summer, it's different. The absence of structure makes some people anxious. Other people plan summer ahead, which puts them in depression if their plans failed.
2 Some people hate the hot weather
Some people simply hate the heat, the excessive sweating and the bugs flying around them, as many of them feel disgusted from insects. This affects their mood negatively, as the thought that controls their mind during that time is how to stay cool and clean, while neglecting everything else.
3 Introverts hate summer
A study shows that most introverts prefer winter, as it allows them to have more time for themselves. However, summer is usually full of gatherings, parties and group travelings.
4 Many people who live in the city hate summer
People who live in cities claim that it gets more crowded, the traffic becomes worse and the noise becomes unbearable. All of these factors cause stress and anxiety.
5 Many girls hate summer
Some girls are not confident enough with their bodies so they hate hanging out at the beach in swimsuits. Moreover, summer is mostly about fashion, so it gives some girls a hard time to choose what to wear. It is much easier in winter; just boots and coats. (See Why some people prefer winter over summer?)
6 Some countries have summer all year long
Countries like Brazil and Cuba don't really experience winter for long so people get bored from the sunny and hot weather they are in. They miss the cold weather and winter clothes.
7 Summer is full of threats to some people
Some people just prefer the safe environment winter offers. They love to relax while drinking hot drinks under their blankets in the calm atmosphere. On the other hand, they feel insecure in summer with all its dynamic routine.
8 People with FoMO hate summer sometimes
People who experience the 'Fear of Missing Out' phobia are more likely to hate summer, as they want to attend every single event and stay connected to all of their friends, which is a very difficult thing to do in summer. (See Why do I look ugly in Sunlight?)
9 Procrastinators hate summer
Procrastinators prefer winter as they take the 'cold weather' as the best excuse to skip or delay some of their tasks. However, in summer, they can not use this excuse anymore. Some of them may even feel guilty when skipping their tasks, as they are not able to convince themselves with any excuse.
10 Workaholics hate summer
Some people are addicted to work, especially Type A Personality. They find that summer break is a waste of time; they prefer finishing some tasks during this break. Some school/college students even find summer break a bit boring without studying.