isophenomenal

from The Century Dictionary.

• Having the same or very similar phenomena; specifically
• In phenology, having the same dates of sprouting, budding, flowering, fruiting, ripening, etc.
• In terrestrial magnetism, having the same magnetic declination, inclination, force, secular variation, diurnal variation, etc.
• In meteorology, having the same frequency of cloudy or rainy weather, or similar atmospheric conditions in general.