If $\text{JUNE}\to 10-21-14-5$, then $\text{JULY}$ will be:

Let's check the position numbers of the letters in $\text{JUNE}$ within the standard alphabetical order ($\text{A}=1,\text{B}=2,\dots ,\text{Z}=26$):
* $\text{J}=10$
* $\text{U}=21$
* $\text{N}=14$
* $\text{E}=5$

The logic is exactly the standard alphabetical positional values of each letter.
Applying this same logic to $\text{JULY}$:

* $\text{J}=10$
* $\text{U}=21$
* $\text{L}=12$
* $\text{Y}=25$

Therefore, the code for $\text{JULY}$ is $10-21-12-25$.