Matplotlib Basemap устарела в пользу Cartopy. Вот код, который позволит вам построить ваши данные в Великобритании.
import numpy as np
import cartopy
import cartopy.crs as ccrs
import cartopy.feature as cfeature
import matplotlib.pyplot as plt
import matplotlib.ticker as mticker
import pandas as pd
long_list = np.arange(-179.5, 180, 1)
lat_list = np.arange(-89.5, 90, 1)
value_dict = {'latitude':[51.0, 51.2, 53.4, 54.5],
'longitude':[-1.1, -1.3, -0.2, -0.9]}
#replace this with your df
df = pd.DataFrame(value_dict)
proj = ccrs.PlateCarree(central_longitude=0)
fig, ax = plt.subplots(subplot_kw=dict(projection=proj), figsize=(16,16))
ax.set_extent([-10, 3, 48, 61], crs=ccrs.PlateCarree())
fig.canvas.draw()
fig.tight_layout()
ax.add_feature(cfeature.LAND, facecolor='0.25')
ax.add_feature(cfeature.BORDERS, zorder=10)
ax.scatter(df['longitude'].values.tolist(), df['latitude'].values.tolist())
gl = ax.gridlines(crs=proj, draw_labels=False, alpha=1, linewidth=0.25)
gl.xlocator = mticker.FixedLocator(long_list)
gl.ylocator = mticker.FixedLocator(lat_list)
plt.show()