SearbornでURLError: <urlopen error [SSL: CERTIFICATE_VERIFY

使用環境
Mac
Pythonバージョン3．6.8

Jupyterで

Python
1tips = sns.load_dataset("tips")

を実行するとSSL: CERTIFICATE_VERIFY_FAILEDのエラーが表示されます。

import ssl

を試しましたが、同様のエラーが出てしまいます。
どのように解決できるでしょうか？

エラー詳細です

---------------------------------------------------------------------------
SSLError                                  Traceback (most recent call last)
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py in do_open(self, http_class, req, **http_conn_args)
   1317                 h.request(req.get_method(), req.selector, req.data, headers,
-> 1318                           encode_chunked=req.has_header('Transfer-encoding'))
   1319             except OSError as err: # timeout error
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py in request(self, method, url, body, headers, encode_chunked)
   1238         """Send a complete request to the server."""
-> 1239         self._send_request(method, url, body, headers, encode_chunked)
   1240 
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py in _send_request(self, method, url, body, headers, encode_chunked)
   1284             body = _encode(body, 'body')
-> 1285         self.endheaders(body, encode_chunked=encode_chunked)
   1286 
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py in endheaders(self, message_body, encode_chunked)
   1233             raise CannotSendHeader()
-> 1234         self._send_output(message_body, encode_chunked=encode_chunked)
   1235 
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py in _send_output(self, message_body, encode_chunked)
   1025         del self._buffer[:]
-> 1026         self.send(msg)
   1027 
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py in send(self, data)
    963             if self.auto_open:
--> 964                 self.connect()
    965             else:
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py in connect(self)
   1399             self.sock = self._context.wrap_socket(self.sock,
-> 1400                                                   server_hostname=server_hostname)
   1401             if not self._context.check_hostname and self._check_hostname:
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/ssl.py in wrap_socket(self, sock, server_side, do_handshake_on_connect, suppress_ragged_eofs, server_hostname, session)
    406                          server_hostname=server_hostname,
--> 407                          _context=self, _session=session)
    408 
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/ssl.py in __init__(self, sock, keyfile, certfile, server_side, cert_reqs, ssl_version, ca_certs, do_handshake_on_connect, family, type, proto, fileno, suppress_ragged_eofs, npn_protocols, ciphers, server_hostname, _context, _session)
    816                         raise ValueError("do_handshake_on_connect should not be specified for non-blocking sockets")
--> 817                     self.do_handshake()
    818 
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/ssl.py in do_handshake(self, block)
   1076                 self.settimeout(None)
-> 1077             self._sslobj.do_handshake()
   1078         finally:
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/ssl.py in do_handshake(self)
    688         """Start the SSL/TLS handshake."""
--> 689         self._sslobj.do_handshake()
    690         if self.context.check_hostname:
SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:847)
During handling of the above exception, another exception occurred:
URLError                                  Traceback (most recent call last)
<ipython-input-9-c8bcbf89f996> in <module>
----> 1 tips = sns.load_dataset("tips")
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/seaborn/utils.py in load_dataset(name, cache, data_home, **kws)
    426                                   os.path.basename(full_path))
    427         if not os.path.exists(cache_path):
--> 428             urlretrieve(full_path, cache_path)
    429         full_path = cache_path
    430 
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py in urlretrieve(url, filename, reporthook, data)
    246     url_type, path = splittype(url)
    247 
--> 248     with contextlib.closing(urlopen(url, data)) as fp:
    249         headers = fp.info()
    250 
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py in urlopen(url, data, timeout, cafile, capath, cadefault, context)
    221     else:
    222         opener = _opener
--> 223     return opener.open(url, data, timeout)
    224 
    225 def install_opener(opener):
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py in open(self, fullurl, data, timeout)
    524             req = meth(req)
    525 
--> 526         response = self._open(req, data)
    527 
    528         # post-process response
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py in _open(self, req, data)
    542         protocol = req.type
    543         result = self._call_chain(self.handle_open, protocol, protocol +
--> 544                                   '_open', req)
    545         if result:
    546             return result
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py in _call_chain(self, chain, kind, meth_name, *args)
    502         for handler in handlers:
    503             func = getattr(handler, meth_name)
--> 504             result = func(*args)
    505             if result is not None:
    506                 return result
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py in https_open(self, req)
   1359         def https_open(self, req):
   1360             return self.do_open(http.client.HTTPSConnection, req,
-> 1361                 context=self._context, check_hostname=self._check_hostname)
   1362 
   1363         https_request = AbstractHTTPHandler.do_request_
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py in do_open(self, http_class, req, **http_conn_args)
   1318                           encode_chunked=req.has_header('Transfer-encoding'))
   1319             except OSError as err: # timeout error
-> 1320                 raise URLError(err)
   1321             r = h.getresponse()
   1322         except:
URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:847)>

宜しくお願い致します。