A Walter-Lieth climate diagram (climograph) is the canonical visualization of a location's annual climate, plotting monthly mean temperature and monthly precipitation over the twelve months on a single panel. It uses the classic 1:2 axis-scaling convention where 10 °C on the temperature axis aligns with 20 mm on the precipitation axis, so the relationship between the two curves directly reveals water availability: where precipitation exceeds the temperature curve the period is humid (filled blue/hatched), and where the temperature curve rises above precipitation the period is arid (filled red/dotted). A header carries station metadata and annual means, while frost indicators along the baseline mark cold months.
# anyplot.ai
# climograph-walter-lieth: Walter-Lieth Climate Diagram
# Library: makie 0.22.10 | Julia 1.11.9
# Quality: 90/100 | Created: 2026-06-15
using CairoMakie
using Colors
using Statistics
const THEME = get(ENV, "ANYPLOT_THEME", "light")
const PAGE_BG = THEME == "light" ? colorant"#FAF8F1" : colorant"#1A1A17"
const ELEVATED_BG = THEME == "light" ? colorant"#FFFDF6" : colorant"#242420"
const INK = THEME == "light" ? colorant"#1A1A17" : colorant"#F0EFE8"
const INK_SOFT = THEME == "light" ? colorant"#4A4A44" : colorant"#B8B7B0"
const INK_MUTED = THEME == "light" ? colorant"#6B6A63" : colorant"#A8A79F"
# Temperature->red, precipitation->blue: universal climate diagram convention
# (semantic exception to Imprint palette ordinal ordering)
const TEMP_COL = colorant"#AE3030" # Imprint matte red
const PRECIP_COL = colorant"#4467A3" # Imprint blue
# Station: fictional Anatolian-style semi-arid continental climate
# 1991-2020 climate normals; one frost month, clear summer arid period
const STATION = "Anatolian Station"
const ELEV = 894
const MLBLS = ["J","F","M","A","M","J","J","A","S","O","N","D"]
const TEMP_ARR = Float64[-0.5, 1.2, 6.5, 12.0, 17.0, 21.0, 25.0, 25.0, 20.5, 14.0, 7.5, 2.0]
const PREC_ARR = Float64[38.0, 34.0, 40.0, 46.0, 52.0, 30.0, 14.0, 10.0, 18.0, 26.0, 34.0, 40.0]
const ANN_T = round(mean(TEMP_ARR); digits=1)
const ANN_P = Int(round(sum(PREC_ARR)))
const xs = collect(1.0:12.0)
const prec_sc = PREC_ARR ./ 2.0 # Walter-Lieth 1:2 scaling (10 degC = 20 mm)
# Y limits: buffer below -10 for the frost indicator band
const Y_BOT = -13.0
const Y_TOP = 35.0
const FRO_BOT = -13.0
const FRO_TOP = -11.0
fig = Figure(
size = (1600, 900),
fontsize = 14,
backgroundcolor = PAGE_BG,
)
# Left axis: temperature (degrees C)
ax = Axis(
fig[1, 1];
title = "climograph-walter-lieth · julia · makie · anyplot.ai",
titlesize = 18,
titlecolor = INK,
backgroundcolor = PAGE_BG,
ylabel = "Temperature (°C)",
ylabelsize = 15,
ylabelcolor = INK,
xlabelcolor = INK,
xticklabelsize = 13,
yticklabelsize = 13,
xticklabelcolor = INK_SOFT,
yticklabelcolor = INK_SOFT,
xtickcolor = INK_SOFT,
ytickcolor = INK_SOFT,
leftspinecolor = INK_SOFT,
bottomspinecolor = INK_SOFT,
topspinevisible = false,
rightspinevisible = false,
xgridvisible = false,
ygridvisible = false,
xticks = (collect(1:12), MLBLS),
yticks = collect(-10:10:30),
)
ylims!(ax, Y_BOT, Y_TOP)
# Right axis: precipitation (mm), scaled 2:1 against the temperature axis
# ylims are set so that 10 degC on the left = 20 mm on the right
ax_r = Axis(
fig[1, 1];
yaxisposition = :right,
backgroundcolor = :transparent,
rightspinecolor = INK_SOFT,
yticklabelcolor = INK_SOFT,
ytickcolor = INK_SOFT,
topspinevisible = false,
leftspinevisible = false,
bottomspinevisible = false,
xticksvisible = false,
xticklabelsvisible = false,
xlabelvisible = false,
xgridvisible = false,
ygridvisible = false,
ylabel = "Precipitation (mm)",
ylabelsize = 15,
ylabelcolor = INK,
yticklabelsize = 13,
yticks = ([0.0, 20.0, 40.0, 60.0], ["0", "20", "40", "60"]),
)
ylims!(ax_r, Y_BOT * 2, Y_TOP * 2)
linkxaxes!(ax, ax_r)
xlims!(ax, 0.5, 12.5)
# Humid fill (blue): months where precipitation curve exceeds temperature curve
band!(ax, xs, TEMP_ARR, max.(TEMP_ARR, prec_sc); color = (PRECIP_COL, 0.40))
# Arid fill (red): months where temperature curve exceeds precipitation curve
band!(ax, xs, min.(TEMP_ARR, prec_sc), TEMP_ARR; color = (TEMP_COL, 0.30))
# Temperature line (on left axis)
lines!(ax, xs, TEMP_ARR; color = TEMP_COL, linewidth = 2.5)
# Precipitation line (on right axis, raw mm values)
lines!(ax_r, xs, PREC_ARR; color = PRECIP_COL, linewidth = 2.5)
# Dashed 0 degC reference line
hlines!(ax, [0.0]; color = (INK_SOFT, 0.5), linewidth = 1.0, linestyle = :dash)
# Frost indicator blocks for months with mean T < 0 degC
for (i, t) in enumerate(TEMP_ARR)
if t < 0.0
poly!(ax,
[Point2f(i - 0.5, FRO_BOT), Point2f(i + 0.5, FRO_BOT),
Point2f(i + 0.5, FRO_TOP), Point2f(i - 0.5, FRO_TOP)];
color = PRECIP_COL, strokewidth = 0)
end
end
# Station metadata header (data coordinates on left axis)
text!(ax, 1.0, 34.0;
text = "$(STATION) ($(ELEV) m a.s.l.)",
fontsize = 16,
color = INK,
align = (:left, :top),
)
text!(ax, 1.0, 29.5;
text = "Mean T = $(ANN_T) °C · Annual P = $(ANN_P) mm (1991–2020)",
fontsize = 13,
color = INK_SOFT,
align = (:left, :top),
)
# Legend
leg_elems = [
LineElement(color = TEMP_COL, linewidth = 2.5),
LineElement(color = PRECIP_COL, linewidth = 2.5),
PolyElement(color = (TEMP_COL, 0.30), strokecolor = :transparent),
PolyElement(color = (PRECIP_COL, 0.40), strokecolor = :transparent),
PolyElement(color = PRECIP_COL, strokecolor = :transparent),
]
leg_labels = [
"Mean temperature",
"Precipitation",
"Arid period (T > P/2)",
"Humid period (P/2 > T)",
"Frost month (mean T < 0 °C)",
]
Legend(fig[1, 2], leg_elems, leg_labels;
framecolor = (INK_SOFT, 0.3),
backgroundcolor = ELEVATED_BG,
labelcolor = INK,
framevisible = true,
framewidth = 1,
patchsize = (22, 12),
rowgap = 6,
padding = (10, 10, 10, 10),
)
colsize!(fig.layout, 1, Relative(0.82))
save("plot-$(THEME).png", fig; px_per_unit = 2)
Part of Walter-Lieth Climate Diagram on anyplot.ai.