Can the weather such as wind have any effect on the trajectory of spells in Harry Potter?

Question

Can spells change direction/trajectory if it was really windy? Since the wind tends to make things fly away, such as the picture below, where the trees and and pieces of the roof are sent flying, can they also change the trajectory of spells?

Answer 1

my Answer is no.

First example is the quidditch match at third year between Hufflepuff and Gryffindor. There is a storm(strong winds) going on during the match, dementors attack, harry falls off from his broom but Dumbledore's spell to harry which saves him from hitting the ground is right on target.

The second one is the runaway at Deathly Hallows with brooms. They are flying on very high attitudes and when they target their spells against Death Eaters and vice versa, they target right onto the face.

I do not know any other case where a windy weather is present, but from @BlueMoon93's comment, we know that spells do not bounce off solid objects they just explode on where they hit. For example, the fight between Harry and Draco in toilet in Half-Blood Prince.

Answer 2

Probably not (but it might depend on the spell).

Atayenel correctly points out the windy Quidditch match in which Dumbledore uses a spell (seemingly without much effort) to save Harry from a nasty fall.

Among the spells we know about, we're given examples of:

• Spells that don't require a target, like the Wand-Lighting Charm;
• Spells that require a target, but don't need line-of-sight or line-of-effect (in The Order of the Phoenix, Fred and George each Summon their brooms-- one of which even breaking out of its tether in the process-- without seeing them);
• Spells that require only general-direction targeting (on the occasions when Harry conjures a Patronus to ward off dementors, the Patronus does most of its own work but charges in the direction it's pointed);
• Spells that can be blocked by physical objects (during the graveyard scene at the end of The Goblet of Fire, Harry avoids some Death Eaters' spells by ducking behind a large gravestone);
• Spells that require pinpoint accuracy (during the Harry/Draco bathroom fight in The Half-Blood Prince, one of Draco's hexes misses Harry by inches).

We don't have any specific examples of a spell being disrupted by bad weather; but since spell requirements seem to run a wide gamut, it's possible there are some that would be.

Answer 3

I don't have the book in front of me, but if memory serves, during the battle at the end of HBP, Snape casts a spell that misses Harry so narrowly, the wind of it's passing ruffles Harrys' hair. From this, I think that at least some spells must have some mass, since they displace air, and conversely, should be effected by wind. I don't recall any canon mentions of lessons on adjusting aim in windy conditions, but I'm guessing that, as with archery and guns, windy conditions must be taken into account, at least for some spells.