fig.update_traces(xhoverformat="%b") # for x unified
fig.update_traces(yhoverformat="Month: %b") # for y unified

hov_text= [f'🌀 Wind Speed <br><br>{d}<br>Daily average: {w} km/h'
           for d, w in zip(dff['date'].dt.strftime('%B %d,%Y'), dff['wind_daily_average'])]

fig = go.Figure()
fig.add_scatter(hovertext=hov_text, hoverinfo='text', ...)

# remove title
fig.update_layout(hovertitle = dict(text=None))

# same title for every x value
fig.update_layout(hovertitle = dict(text="Always the same title"))

# set it to a df variable that is not the x value, or that is a combination of values (similar to the current workaround)
fig.update_layout(hovertitle = dict(text=df["my_custom_value"]))
fig.update_layout(hovertitle = dict(text=f'Max stock price in period: {df["max_by_quarter"]}'))