Please note that this website is currently under construction
This is a new climate classification that was created and developed by Caleb Dickinson.
Within the Dickinson Climate Classification, every climate where life could persist, real or speculative, is categorized with reasonable granularity (Dickinson, 2026).
This system is particularly suited for identifying emergent climates with no modern analogues and situating Earth’s climates within a broader, formally defined climate state space.
The projections shown on this website use a high-emissions scenario because it allows the Dickinson Climate Classification to examine extreme climate states that could emerge in the coming centuries. We explore the broader climate state space defined by the system and demonstrate how the classification can be used to describe and categorize climate regimes that do not exist on Earth today.
Each climate is measured with 2 or 3 parts, depending on whether the climate is classified by aridity.
The first part measures climate zones by measuring the average temperature of the coldest month in Celsius.
H = Hypercaneal. 50 and above (hypothetical)
X = Uninhabitable. 40 - 50 (hypothetical)
Z = Hyperequatorial. 30 - 40
A = Equatorial. 20 - 30
B = Tropical. 10 - 20
C = Subtropical. 0 - 10
D = Temperate. -10 - 0
E = Continental. -20 - -10
F = Subarctic. -30 - -20
G = Arctic. -40 - -30
Y = Superarctic. Below -40
The second part measures aridity zones.
To see the method we used to determine aridity zones, please visit the Classification page of this website.
Aridity does not appear to be relevant to the classification of climates that fall within subarctic, arctic, superarctic, cold summer, very cold summer, freezing summer, or frigid summer zones.
Climate classifications that fall within these zones are not measured by aridity.
H = Humid
G = Semihumid
S = Semiarid
D = Arid
M = Mediterranean
W = Monsoon
V = Semiarid Monsoon
The third part measures the severity of the summers by measuring the average temperature of the warmest month in Celsius.
H = Hypercaneal Summer. 50 and above (hypothetical)
X = Hyperthermal Summer. 40 - 50
Z2 = Scorching Summer. 35 - 40
Z1 = Very Hot Summer. 30 - 35
A2 = Hot Summer. 25 - 30
A1 = Warm Summer. 20 - 25
B2 = Cool Summer. 15 - 20
B1 = Cold summer. 10 - 15
C2 = Very Cold Summer. 5 - 10
C1 = Freezing Summer. 0 - 5
Y = Frigid Summer. Below 0
For baseline climate conditions, we used the 1981–2010 CHELSA v2.1 climatological normals, including Penman–Monteith potential evapotranspiration fields (Allen et al., 1998; Karger et al., 2017; Brun et al., 2022). For projections, we used the 2011-2040, 2041-2070, and 2071-2100 CHELSA-downscaled UKESM SSP5-8.5 projection normals. Hargreaves PET (Hargreaves and Samani, 1985) was computed for all periods from temperature data, and the baseline ratio between Hargreaves and Penman–Monteith PET during 1981–2010 was applied as a multiplicative bias correction to projected Hargreaves PET to ensure continuity with the Penman–Monteith reference climatology.
SSP5-8.5 represents a high-growth, energy-intensive future dominated by fossil fuel use, resulting in very high greenhouse gas emissions—making it a widely used analogue for present-day trajectories under minimal mitigation efforts (Riahi et al., 2017, Schwalm et al., 2020). UKESM1-0-LL was selected due to its higher climate sensitivity and stronger land–atmosphere coupling, which makes it useful for bounding upper-risk habitability outcomes.
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