Throughout the day note how the light moves through your space. I know from experience that the light in your space is never exactly what you think it is. You can either note shady spots throughout different times of the day, or note the sunny spots. Be sure to note the softscapes (gardens) AND the hardscapes. Is a certain spot shaded by a deciduous tree in the summer, but warmed by the winter sun? Is there a spot that stays shady all year causing ice to collect in the winter?
Chances are good that your space has little microclimates. I have a small yard and can reliably winter things over well in the pocket of space between my house and garage. Look for little areas where plants stay green longer or green up sooner in the spring. Hardscapes are great at absorbing heat during the day and releasing it at night, so you likely have temperature differences close to your hardscapes. Don’t forget to highlight these areas on a map.
Is there a specific pattern to the way the wind blows through your property? Is your space like a punishing wind tunnel, or does a slight breeze work to cool things off? When it snows, does it drift in certain areas? Which direction does the wind come from? Are there areas that are absolutely still? Powdery mildew and other fungal infections are a good indicator of stagnant air.