<p>To put it in simple terms: at the equinox, the Earth's axis is halfway in its apparent movement from pointing <em>away</em> from the Sun (northern winter solstice) to pointing <em>towards</em> the Sun (northern summer solstice).</p>
<p>At each equinox, the Earth's axis is exactly at right angles to where the Sun is, which means the Sun rises due east and sets due west, and day and night are of equal length.</p>
<p>The difference between the two is that after the Spring (or Vernal) Equinox – in late March for the northern hemisphere – the days are longer than the nights, while after the Autumnal Equinox – in late September – the nights are longer than the days.</p>

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2024-09-02T23:55:25.110Z
2024-09-02T23:55:25.110Z
Chappo Hasn't Forgotten
<p>I want to know how the position of the Earth relative to the sun determines when it's fall or spring if on both equinoxes the incidence of light is the same. What makes these two seasons different from each other?</p>

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2024-09-02T23:37:00.007Z
The difference is in where the Sun is heading.  Spring is when the Sun appears to move from South of the equitorial plane to North of the equtorial plane, although the instant of the equinox is when it's on the equitorial plane.
Greg Miller
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2024-09-02T23:38:44.967Z
Also, the equinox is in Sept rather than Oct, and that is the fall equinox for the Northern hemisphere.
Greg Miller
CC BY-SA 4.0
2024-09-03T08:09:41.720Z
I recommend you change the title as it is very confusing!
deep64blue
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2024-09-03T11:59:11.637Z
_"What makes these two seasons different from each other?"_ If you're asking why the weather distribution around late March is different to late September, that's a very different question than just astronomy. (The temperature, humidity, pressure etc. on the entire Earth does not change that quickly, and local weather is affected by what happens on Earth during preceding months, and the effect is very complex and very dependent on location and geography.) Maybe rephrase your question to be clear what you're asking.
JiK
CC BY-SA 4.0
2024-09-04T12:23:10.450Z
Our planet has thermal inertia. The solar energy accumulated in previous days and weeks does not dissipate in a moment. Before and after sping equinox incoming solar energy continues to increase (in Northern hemisphere, the opposite for Southern). And for autumn equinox it's reversed. The same reason is why usually July is the hottest month for Northern hemisphere, not June, although solar energy peaks in June 22 - Earth accumulates solar energy from June and needs significant time to dissipate it, and incoming energy in July is just slightly less than in June, so temperature continues to rise
Heopps
<solar-system><earth><earths-orbit>
What makes the spring equinox happen on october instead of fall on the north hemisphere?
Tito Morenno Pontes e Souza
# What makes the spring equinox happen on october instead of fall on the north hemisphere?

(Asked by: username_0 on 2024-09-02)

I want to know how the position of the Earth relative to the sun determines when it's fall or spring if on both equinoxes the incidence of light is the same. What makes these two seasons different from each other?

**Tags:** solar-system, earth, earths-orbit
> **Comments:**
> **username_1**: The difference is in where the Sun is heading.  Spring is when the Sun appears to move from South of the equitorial plane to North of the equtorial plane, although the instant of the equinox is when it's on the equitorial plane.  
> **username_1**: Also, the equinox is in Sept rather than Oct, and that is the fall equinox for the Northern hemisphere.  
> **username_2**: I recommend you change the title as it is very confusing!  
> **username_3**: _"What makes these two seasons different from each other?"_ If you're asking why the weather distribution around late March is different to late September, that's a very different question than just astronomy. (The temperature, humidity, pressure etc. on the entire Earth does not change that quickly, and local weather is affected by what happens on Earth during preceding months, and the effect is very complex and very dependent on location and geography.) Maybe rephrase your question to be clear what you're asking.  
> **username_4**: Our planet has thermal inertia. The solar energy accumulated in previous days and weeks does not dissipate in a moment. Before and after sping equinox incoming solar energy continues to increase (in Northern hemisphere, the opposite for Southern). And for autumn equinox it's reversed. The same reason is why usually July is the hottest month for Northern hemisphere, not June, although solar energy peaks in June 22 - Earth accumulates solar energy from June and needs significant time to dissipate it, and incoming energy in July is just slightly less than in June, so temperature continues to rise  

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## 1 answers

### Answer by username_5 on 2024-09-02. Score: 3

To put it in simple terms: at the equinox, the Earth's axis is halfway in its apparent movement from pointing *away* from the Sun (northern winter solstice) to pointing *towards* the Sun (northern summer solstice).

At each equinox, the Earth's axis is exactly at right angles to where the Sun is, which means the Sun rises due east and sets due west, and day and night are of equal length.

The difference between the two is that after the Spring (or Vernal) Equinox – in late March for the northern hemisphere – the days are longer than the nights, while after the Autumnal Equinox – in late September – the nights are longer than the days.


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