Thank you for the update Sylvastreak.

I can't tell if a heatwave would affect your equipment, but if there is an issue around your area due to weather (not necessarily with your connection itself) it could cause these kinds of errors if you are being routed though it. As for what you can do, try some of the suggestions below to make sure that nothing is interfering with your connection:

The game will use the Internet Explorer web browser to connect to the internet. Open Internet Explorer, then open the "Tools" setting, go to "Internet Options" and adjust the following settings:
- Under the "General" tab, please delete ALL browser history.
- Under the "Security" tab, please move the slider to the lowest possible settings or no higher than "Medium"
- Under the "Privacy" tab, please move the slider to the lowest possible settings or to "Allow All Cookies"
- Under the "Advanced" tab, please make sure that "Allow software to run or install even if signature is invalid" is CHECKED.
- Make sure that all SSL and TLS (EXCEPT SSL 3.0) are CHECKED. [SSL 3.0 should be UNCHECKED]
- Hit "Apply" to save the settings, and then "OK, to close the Internet Options menu.
- Right-Click on the FFXIV launcher icon and select "Properties"
- Go to the "Compatibility" tab, and change the compatibility mode to "Windows 7"
- Hit "Apply", then "OK" to save the changes.
- Please RESTART your PC now. Once your PC has been restarted, Right-Click the FFXIV launcher icon once more and select "Run as Administrator"

Check the following Port Ranges on your router/modem to ensure that the following Port Ranges have been opened/forwarded/triggered:
▼TCP
54992 through 54994,
55006 through 55007,
55021 through 55040

Your ISP may forward these ports for you.*

Makes sure that your anti-virus/firewall is not interfering with Final Fantasy XIV. Also, close out any unnecessary programs that may be running in the background.

We hope we can be of assistance in helping you enjoy the exciting world of Final Fantasy XIV!