Network latency or packet loss between the client and Snowflake's regional endpoint. Firewall or proxy blocking or delaying the initial TCP handshake or TLS negotiation. Snowflake account URL is incorrect, routing to an unreachable endpoint. login_timeout is set too low for the network conditions. Snowflake service degradation or maintenance in the target region

Increase the login timeout: snowflake.connector.connect(..., login_timeout=60).. Verify the account URL is reachable: curl -I https:// .snowflakecomputing.com.. Check that TCP port 443 is open from the client to Snowflake: telnet .snowflakecomputing.com 443.. Review proxy settings — ensure HTTPS_PROXY is set if required by the network.. Check Snowflake's status page (status.snowflake.com) for active incidents in your region.

Medium severityconnectionSnowflake →

Power BI Refresh Error:
251011

What does this error mean?

The Python connector timed out while attempting to establish a connection to Snowflake. The server did not respond within the configured login timeout window, indicating a network path issue or Snowflake service availability problem.

Common causes

1Network latency or packet loss between the client and Snowflake's regional endpoint
2Firewall or proxy blocking or delaying the initial TCP handshake or TLS negotiation
3Snowflake account URL is incorrect, routing to an unreachable endpoint
4login_timeout is set too low for the network conditions
5Snowflake service degradation or maintenance in the target region

How to fix it

1Increase the login timeout: snowflake.connector.connect(..., login_timeout=60).
2Verify the account URL is reachable: curl -I https://<account>.snowflakecomputing.com.
3Check that TCP port 443 is open from the client to Snowflake: telnet <account>.snowflakecomputing.com 443.
4Review proxy settings — ensure HTTPS_PROXY is set if required by the network.
5Check Snowflake's status page (status.snowflake.com) for active incidents in your region.

Frequently asked questions

What is the default login_timeout in the Python connector?

The default is 120 seconds. You can reduce it for faster failure detection or increase it for high-latency networks.

Does a connection timeout affect ongoing queries?

No — login_timeout only applies to the initial connection establishment. For query execution timeouts, use network_timeout or STATEMENT_TIMEOUT_IN_SECONDS.

Official documentation: https://github.com/snowflakedb/snowflake-connector-python/blob/main/src/snowflake/connector/errorcode.py