Matplotlib subplots not working with seaborn distplot about proplot HOT 5 CLOSED

import pandas as pd
import xarray as xr
import numpy as np
import seaborn as sns

import proplot as plot
import calendar

def drop_nans_and_flatten(dataArray: xr.DataArray) -> np.ndarray:
    """flatten the array and drop nans from that array. Useful for plotting histograms.

    Arguments:
    ---------
    : dataArray (xr.DataArray)
        the DataArray of your value you want to flatten
    """
    # drop NaNs and flatten
    return dataArray.values[~np.isnan(dataArray.values)]


# create dimensions of xarray object
times = pd.date_range(start='1981-01-31', end='2019-04-30', freq='M')
lat = np.linspace(0, 1, 224)
lon = np.linspace(0, 1, 176)

rand_arr = np.random.randn(len(times), len(lat), len(lon))

# create xr.Dataset
coords = {'time': times, 'lat':lat, 'lon':lon}
dims = ['time', 'lat', 'lon']
ds = xr.Dataset({'precip': (dims, rand_arr)}, coords=coords)
ds['month'], ds['year'] = ds['time.month'], ds['time.year']

f, axs = plot.subplots(nrows=4, ncols=3, axwidth=1.5, figsize=(8,12), share=2) # share=3, span=1,
axs.format(
    xlabel='Precip', ylabel='Density', suptitle='Distribution', 
)

month_abbrs = list(calendar.month_abbr)
mean_ds = ds.groupby('time.month').mean(dim='time')
flattened = []
for mth in np.arange(1, 13):
    ax = axs[mth - 1]
    ax.set_title(month_abbrs[mth])
    print(f"Plotting {month_abbrs[mth]}")
    flat = drop_nans_and_flatten(mean_ds.sel(month=mth).precip)
    flattened.append(flat)
    sns.distplot(flat, ax=ax, **{'kde': False})

Plotting Jan
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-1-bea6a445aa3a> in <module>
     46     flat = drop_nans_and_flatten(mean_ds.sel(month=mth).precip)
     47     flattened.append(flat)
---> 48     sns.distplot(flat, ax=ax, **{'kde': False})
     49

~/miniconda3/envs/maize-Toff/lib/python3.7/site-packages/seaborn/distributions.py in distplot(a, bins, hist, kde, rug, fit, hist_kws, kde_kws, rug_kws, fit_kws, color, vertical, norm_hist, axlabel, label, ax)
    226         ax.hist(a, bins, orientation=orientation,
    227                 color=hist_color, **hist_kws)
--> 228         if hist_color != color:
    229             hist_kws["color"] = hist_color
    230

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()