w_data =
{'1950-01-01':
  {'date': '1950-01-01', 'prcp': 0.06, 'snow': 0.0, 'snwd': 0.0, 'tmax': 49.0, 'tmin': 42.0, 'mean': 45.5},
'1950-01-02':
  {'date': '1950-01-02', 'prcp': 0.65, 'snow': 0.0, 'snwd': 0.0, 'tmax': 57.0, 'tmin': 48.0, 'mean': 52.5},
'1950-01-03':
{'date': '1950-01-03', 'prcp': 2.82, 'snow': 0.0, 'snwd': 0.0, 'tmax': 65.0, 'tmin': 51.0, 'mean': 58.0}
}

# keys are
# '1950-01-01'
# '1950-01-02'
# '1950-01-03'

# values for those keys are
# {'date': '1950-01-01', 'prcp': 0.06, 'snow': 0.0, 'snwd': 0.0, 'tmax': 49.0, 'tmin': 42.0, 'mean': 45.5}
# {'date': '1950-01-02', 'prcp': 0.65, 'snow': 0.0, 'snwd': 0.0, 'tmax': 57.0, 'tmin': 48.0, 'mean': 52.5}
# {'date': '1950-01-03', 'prcp': 2.82, 'snow': 0.0, 'snwd': 0.0, 'tmax': 65.0, 'tmin': 51.0, 'mean': 58.0}

print(w_data['1950-01-01'])

# prcp on 1950-01-01
x = w_data['1950-01-01']
print(x['prcp'])
# or
print(w_data['1950-01-01']['prcp'])