Fear of Thunder

"Tidus: Are you that scared? Rikku: Mm-hm. When I was little, a fiend attacked me while I was swimming at the beach. My brother tried to beat it back with a spell. *Squeaks at another thunderclap* But he missed and hit me instead! It was a Thunder spell -- "Bzzzzzzt!" Tidus: Ouch! Rikku: I've been scared of lightning ever since."

- Final Fantasy X

Your otherwise capable or serious character has an inordinate fear of thunderstorms. This is a primal, almost childish fear that surprises other characters, although it's not always played for laughs. The actual name of this fear is "Brontophobia" or "Astraphobia." However, the former suggests a fear of incorrectly-named, four-legged sauropods while the latter, a horror of affordable German family cars. It also happens to animals, especially dogs.

This trope is Real Life Older Than Feudalism, with the fear of thunder being a prime defining weakness of the Julius Caesar and the Julio-Claudian dynasty of Ancient Rome. According to Roman historians Tacitus and Seutonius, the Julii family had considered thunder to be their own personal curse, as every time they were caught in a thunderstorm away from home in Rome something awful was going to happen. This likely stems from Julius Caesar's stint as Pontifex Maximus, the most powerful priest in Rome, where receiving fairly ludicrous auguries about such things happened frequently. (They also had a thing about owls.)

Augustus had a particularly strong fear of thunder because a slave was once struck by lightning right in front of him while traveling. Emperors are recorded as doing any number of things to avert the danger: wearing a bit of sealskin, wearing a laurel wreath, and even (most practically) going underground. (It certainly didn't help that Romans, as a whole, had lots of beliefs and superstitions related to gods of nature. I.e.: Thunder and lighting were associated with Jupiter, the Father of the Gods, and being on the bad side of a pissed off Jupiter was something you really did not want, according to their mentality).

Note that fear of thunder is often treated as silly; after all, it's just a lot of noise. Fear of lightning, on the other hand, is absolutely justified. (And confirmed by Snopes.)

A subtrope of Why Did It Have to Be Snakes?, especially common in Anime. Would be logical in settings with Dramatic Thunder, but the tropes seldom combine.

Anime and Manga

 * Tomboyish Bottle Fairy Tina Foster in Ai Yori Aoshi has a panic attack during a thunderstorm that knocks out the house's electricity.
 * Haruhi Fujioka in Ouran High School Host Club has a particular hatred of thunderstorms despite having an abnormal lack of fear of anything else. This is addressed in what is either a Crowning Moment of Heartwarming, or a Harsher in Hindsight instance of Hey, It's That Voice!
 * Kid Samurai Motoko Aoyama in Love Hina is said to be afraid of lightning, although it never comes up.
 * Samurai Sakura Shinguuji in Sakura Taisen is in fact deathly scared of lightning. Motoko's phobia may be a reference to, or parody of, this.
 * Chiyo-chan, from Azumanga Daioh, is a genius, ridiculously cute, and scared of lightning. In her defense, she's still only 10 years old.
 * In the manga, one of the Yonkoma shows that Sakaki is also scared of lightning.
 * Osaka is scared of lightning too, but she enjoys it. She even peers closer to the window. If this doesn't make sense, remember, this is Osaka we're talking about.
 * After having to endure a rather traumatic car ride with Yukari-sensei, Chiyo-chan is asked by Tomo if she thinks lightning or cars are worse during a particularly bad storm, and promptly suffers a BSOD.
 * Elie, from Rave Master, is a young female Badass Normal who dual wields two high-caliber guns (with highly explosive ammunition too, apparently) and other dangerous ballistic instruments, faces demonic threats with relative frequency, and carries the world's most powerful magic inside her... and is so scared of storms a little zap is enough to send her to the ground quivering and unable to act. In her defense, though, this fear comes from the trauma of being almost killed by extremely powerful lightning spells -- twice.
 * Usagi Tsukino in Sailor Moon had a touch of this throughout the series, though it was particularly played up during an episode of Sailor Moon R in which Chibi-Usa was revealed to have the same fear. The villains used a Monster of the Week to create a massive thunderstorm as a way to ferret out Chibi-Usa, which works when the poor girl becomes so frightened she loses control of her powers after being left alone during the storm. Usagi spends the whole episode freaking out as well, and when she fights the monster later, she's particularly upset with it for ruining her day. This trope is also one of many clues (as if you really needed them) that Chibi-Usa was Usagi's Kid From the Future.
 * Phoenix Wright is revealed in the manga side stories to have a paralyzing fear of storms, though the side stories are generally considered non-canon.
 * Kou Shuurei in Saiunkoku Monogatari goes into fits of screaming terror during thunderstorms, as memorably revealed during her brief stint of posing as a boy to work for Ko Kijin.
 * Kyou from Binbou Shimai Monogatari
 * Lucia of Mermaid Melody Pichi Pichi Pitch possessed this trait.
 * It's played up for Fan Service and Brother-Sister Incest Mikan Yuki of To Love-Ru is scared of storms and Rito used to comfort her.
 * In the Detectives Koshien arc from Detective Conan, a storm starts when the four teenaged detectives are gathered in an old mansion . Once thunder breaks in, Natsuki "Detective of the South" Koshimizu screams in utter horror and collapses to the floor.
 * Filicia Heideman of Sora no Woto, the only visible chink in her Captain Smooth persona.
 * In the first episode of Stitch!, Yuuna is shown to be afraid of lightning.
 * Nano is shown to be afraid of lightning in Nichijou when she walks her Professor to the bathroom during a storm.
 * Aria from Hidan no Aria is quite afraid of thunder. This does present problems in missions where it's raining.
 * Ramba Ral's Zeon crew are completely freaked out when they land on Earth in the middle of a thunderstorm, actually thinking that it's some sort of Federation defense system until Ral corrects them and explains what's going on. A Justified Trope: most of them were born and live in massive, climate-controlled colony stations, and have never been to Earth before.
 * Junpei/J.P. in Digimon Frontier is afraid of thunder and lightning; ironically, he is the Thunder Warrior element of the group.

Comic Books

 * In a Sliver Age Supergirl story, Supergirl dreams a What If in which she was raised by Superman's parents. In one part of the dreams, she wrecks the Kents' house during a thunderstorm.

Film

 * In the film Mongol about the early life of Genghis Khan (called Temujin here), it is explained that Thunderstorms are a cultural fear of the Mongolian people. Of course, Temujin himself is the first one to overcome this fear.
 * Apparently all of the Von Trapp children in The Sound of Music are deadly afraid of thunderstorms, as shown in the scene leading up to "My Favorite Things".
 * In the film Top Hat, a clap of thunder momentarily causes Ginger Rogers to drop her haughty manner towards Fred Astaire.
 * One of the many phobias/unreasoning terrors that the heroine experiences in Hitchock's Marnie.
 * In Arashi no Yoru ni, one of the things that brings Gabu and Mei together when the first meet in a barn on a stormy night is their shared fear of thunder.

Literature

 * Subverted in Romance of the Three Kingdoms, where Cao Cao assesses Liu Bei and says that the two of them are the only true heroes; Liu Bei is immediately mortified by the possibility that Cao Cao might see him as a rival and, thus, someone who the shrewd and powerful Cao Cao will eventually have to kill. Thankfully for him, a bolt of lightning happens to strike at this time, and Liu Bei pretends to cower in fear...thus causing Cao Cao to dismiss him as coward. Cao Cao would eventually regret this; Liu Bei managed to walk off unscathed, and would later become the ruler of one of the rival kingdoms to oppose Cao Cao.
 * In the Swallows and Amazons books by Arthur Ransome, Peggy is afraid of thunder, much to the scorn of her sister Captain Nancy (who isn't afraid of anything). This comes to a head in Missee Lee, where the girls are in a ship under attack by Chinese pirates with cannon, and Nancy comforts Peggy: "That's guns, not thunder!"
 * Josefina from the American Girls Collection (although it's actually the lightning she's afraid of).
 * Fami, from M.A. Bell's Spyhunt, is terrified of thunder, mostly due to the fact that his father died and he went blind during a thunderstorm..
 * Despite this, Fami crosses a roof during a storm in the first book.
 * Marley in Marley and Me is terrified of thunder and the frequent south Florida thunderstorms cause him to frequently destroy the house in fits of fear.
 * The lesser-known character Monks in Oliver Twist is afraid of thunder, and has a good old rant about it at one point. However, in his case it is a pretty legitimate fear.
 * In H.P. Lovecraft's "The Lurking Fear", the Martense clan  share the hereditary trait of being driven to frenzied, violent panic by thunderstorms.
 * In Kate DiCamillo's Because of Winn-Dixie, the dog is horribly afraid of thunderstorms.
 * James Joyce had a fear of thunder and lightning, which he bestowed upon Stephen Dedalus, who serves a Joyce's Author Avatar in and Ulysses. Dedalus, even though he is an atheist, sees thunderstorms as a manifestation of God's power, and believes that thunder is God's punishment against him for failing to meet the last wishes of his dead mother.
 * The official iOS app of the Warrior Cats series claims that Hollyleaf has this - justified, since Ashfur had attempted to murder her and her littermates during a thunderstorm that started a fire.

Video Games

 * In a somewhat ironic twist, Big Bad Colonel Volgin of the third Metal Gear Solid game is afraid of storms. Although this is directly passed on via radio communication from one character to another, there are other subtle hints, such as how Volgin retreats to his quarters during storms and chants a Japanese charm against lighting strikes when forced to be outside while it's raining. This is ironic because Volgin himself has control over electricity, uses it as his primary weapon, and one of his nicknames is "Thunderbolt."
 * Considering he has giant scars all over his body where his electricity burned/ripped his skin, he obviously isn't immune to it.
 * Hell, he doesn't just forget to say his little mantra, he even MOCKS the thunder itself by declaring "Who's afraid of a little thunder?!"
 * Oh, and his subordinate/boyfriend's last name is either a clever way to reinforce said subordinate's resemblance to Raiden or a really jerk-ass bit of bilingual humor. Anyone who disagrees with the previous designation is clearly lying.
 * Tails from the Sonic the Hedgehog series is afraid of lightning in some versions. Especially in the anime OVA. Though the games seem to have removed this character trait, as his element power in Sonic Heroes is Thunder Shoot.
 * Rikku in Final Fantasy X suffers this, due to a traumatic childhood experience of a mis-aimed attempt to protect her from a sea monster using lightning magic. Between that game and its sequel, Final Fantasy X-2, she cures her phobia through the fairly simple method of camping for a week in the Thunder Plains, where there's always lightning. Rikku even reacts in both games to this fear -- in Final Fantasy X, she gives a unique scream (compared to the rest of the team) whenever she's hit with a lightning spell, and in Final Fantasy X-2, she actually says "Astraphobic? Not me!" when actually casting Lightning spells in the Black Mage class. While anyone showing fear at having to walk through the Thunder Plains where one must literally dodge lightning bolts by stepping out of the way is rational, Rikku's reaction is considered to be well over the top by the rest of the party during the storyline.
 * Shion in Xenosaga is traumatized by lightning because her fiancé and parents were both killed during thunderstorms. This also appeared in the anime adaptation of the game.
 * Despite the subversion in the novel, this is played straight in Dynasty Warriors 4 in one of the Shu Endings. Liu Bei is eating with Guan Yu and Zhang Fei when a bolt of lightning strikes, causing Liu Bei to dive under the table in panic while Guan Yu and Zhang Fei Watch.
 * Despite the subversion in the novel, this is played straight in Dynasty Warriors 4 in one of the Shu Endings. Liu Bei is eating with Guan Yu and Zhang Fei when a bolt of lightning strikes, causing Liu Bei to dive under the table in panic while Guan Yu and Zhang Fei Watch.

Western Animation

 * An episode of Shaggy and Scooby-Doo Get A Clue revealed that both the villain and Scooby have lightning issues. Phibes apparently gets so upset that his prosthetic laser gun is fired off when he so much as hears the word "lightning". His plot of the episode revolves around creating a never-ending thunderstorm, thus leaving the severely astraphobic Scooby as a paranoid wreck. Since the lightning bolts are apparently violent and can strike anything, Scooby actually has justification for this. Shaggy drags him along to stop the storm anyway.
 * In both an original storybook and an episode based on it, Franklin Turtle was afraid of thunderstorms. He was worried that his friends would make fun of him, since in most other matters he was normally pretty courageous, but they turned out to be quite understanding.
 * Lola on Charlie and Lola.
 * Subverted on Dexters Laboratory, while laying in his bed during a thundertorm, Dexter dismisses his initial fear by reminding himself of the science behind lightening.
 * Dudley from Tuff Puppy is afraid of thunder. He got over it the same episode that it was introduced.
 * In The Venture Brothers, Dean contemplates living with Dr. Orpheus, fantasizing that he's comforting Triana when she's scared of a storm.
 * Martha and Skits from Martha Speaks are both afraid of thunderstorms. Martha deals with it better than Skits does.

Fan Fiction

 * Fanfiction authors usually invoke this trope in Shipping fanfics.
 * If it is not invoked in a shipping fanfic, it will usually be invoked in a family-fluff fic as an excuse for a child or younger sibling to cuddle with someone.

Real Life

 * John Adams apparently had one of these, making his successful argument in the debate for American independence (which took place during an intense thunderstorm) an even bigger Crowning Moment of Awesome.
 * The Russian composer Tchaikovsky would hide under his bed during thunderstorms. Modern psychologists theorize that he was Brontophobic.
 * Culturally, fear of lightning/thunder is common in the Middle East (where there is little cover in the desert). For this reason, the US Army experiments with nonlethal targeted-energy electric discharge weapons that resemble arc lightning.
 * Many dogs are scared of thunder and loud noises.
 * Likely anybody raised in an area without thunderstorms.
 * And several people raised in areas with frequent thunderstorms, more likely if they've been struck by lightning.