Subarctic

Subarctic climate (also called boreal climate) is a climate characterized by long, usually very cold winters, and short, cool to mild summers. Almost all garden worlds have some subarctic climate.

This type of climate offers some of the most extreme seasonal temperature variations found on any planet: for example on Terra in winter, temperatures can drop to −40 °C and in summer, the temperature may exceed 30 °C. Summers are short in this climate; no more than three months (but at least one month) must have a one day average temperature of at least 10 °C to fall into this category of climate. With up to eleven months of the year where the average temperature is below freezing, all moisture in the soil and subsoil freezes solidly to depths of many meters. Summer warmth is insufficient to thaw more than a few surface meters, so permafrost prevails under most areas not near the boundary of this climate zone.

Most subarctic climates have very little precipitation. Vegetation in subarctic regions is generally of low diversity, as only hardy species can survive the long winters and make use of the short summers. Agricultural potential is generally poor, due to the prevalence of swamps and lakes left by departing ice sheets and short growing seasons.