http://maps.openweathermap.org/maps/2.0/weather/{op}/{z}/{x}/{y}
Parameters:
op - Weather map layer. Full list of available weather map layers here.
z - Number of zoom level
x - Number of x tile coordinate
y - Number of y tile coordinate
date - Date and time of (Unix time, UTC), e.g. date=1527811200.
If you do not specify any date and time, you will get Current weather map.
More information about how to get Current, Forecast and Historical maps you can find here.
opacity - Degree of layer opacity. Available value from 0 to 1 (default - 0.8)
palette - Color palette. You can use custom palettes for each layer.
You can also create a palette for yourself and pass it to the URL as follows {value}:{HEX color};..;{value}:{HEX color}.
More information about it here.
fill_bound - 'true' or 'false'. If 'true', then all weather values outside the specified set of values will be filled by
color corresponding to the nearest specified value (default value - 'false': all weather values outside the specified set
of values are not filled).
arrow_step - Step of values for drawing wind arrows, specify in pixels (default - 32). Parameter only for wind layers (WS10, WND).
use_norm - 'true' or 'false'. If 'true', then the length of the arrows is normalizing
(default - 'false': the length of the arrows is proportional to the speed wind value). Parameter only for wind layers (WS10, WND).