Weather Pattern Heatmap

import matplotlib.pyplot as plt
import numpy as np
from matplotlib.colors import LinearSegmentedColormap
from matplotlib.patches import FancyBboxPatch

fig, ax = plt.subplots(figsize=(14, 8), facecolor='#ffffff')
ax.set_facecolor('#ffffff')

np.random.seed(42)
cities = ['NYC', 'LA', 'Chicago', 'Houston', 'Phoenix', 'Seattle']
months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
temps = np.array([
    [2, 4, 10, 16, 21, 26, 29, 28, 24, 17, 11, 5],
    [15, 16, 17, 18, 20, 22, 25, 26, 25, 22, 18, 15],
    [-3, -1, 5, 12, 18, 24, 27, 26, 22, 14, 6, -1],
    [12, 14, 18, 22, 26, 29, 30, 30, 28, 23, 17, 13],
    [14, 16, 20, 25, 30, 36, 39, 38, 35, 27, 19, 14],
    [6, 7, 9, 12, 15, 18, 21, 21, 18, 13, 8, 5]
])

colors = ['#1e40af', '#3b82f6', '#334155', '#fb923c', '#dc2626']
cmap = LinearSegmentedColormap.from_list('temp', colors, N=256)

cell_w, cell_h = 0.88, 0.82
for i in range(len(cities)):
    for j in range(len(months)):
        val = temps[i, j]
        rect = FancyBboxPatch((j - cell_w/2, i - cell_h/2), cell_w, cell_h,
                               boxstyle="round,pad=0.02,rounding_size=0.12",
                               facecolor=cmap((val+10)/55), edgecolor='#e2e8f0', linewidth=1.5)
        ax.add_patch(rect)
        ax.text(j, i, f'{val}°', ha='center', va='center', color='#1e293b', fontsize=9, fontweight='bold')

ax.set_xlim(-0.5, len(months)-0.5)
ax.set_ylim(-0.5, len(cities)-0.5)
ax.set_aspect('equal')
ax.invert_yaxis()
ax.set_xticks(range(len(months)))
ax.set_yticks(range(len(cities)))
ax.set_xticklabels(months, color='#64748b', fontsize=9, fontweight='500')
ax.set_yticklabels(cities, color='#1e293b', fontsize=10, fontweight='500')

sm = plt.cm.ScalarMappable(cmap=cmap, norm=plt.Normalize(-10, 45))
cbar = plt.colorbar(sm, ax=ax, shrink=0.8, pad=0.02)
cbar.set_label('Temperature (°C)', color='#1e293b', fontsize=11)
cbar.outline.set_edgecolor('#e2e8f0')
plt.setp(plt.getp(cbar.ax.axes, 'yticklabels'), color='#64748b')

for spine in ax.spines.values(): spine.set_visible(False)
ax.tick_params(length=0)
ax.set_title('Average Monthly Temperatures', fontsize=18, color='#1e293b', fontweight='bold', pad=20)
plt.tight_layout()
plt.show()