As of April 4, 2016, Tor Weather has been discontinued.
Tor Weather provided an email notification service to any user who wanted to monitor the status of a Tor node. Upon subscribing, they could specify what types of alerts they would like to receive. The main purpose of Tor Weather was to notify node operators via email if their node was down for longer than a specified period, but other notification types were available, including one where operators would be informed when their node was around long enough to qualify for a t-shirt.
The main reason for discontinuing Tor Weather is the fact that software requires maintenance, and Tor Weather is no exception. Tor Weather was promising t-shirts for relays that have not been around long enough or that provided too little bandwidth to be useful to the network, and it was almost impossible to deny a t-shirt after Tor Weather has promised it. Apart from that, Tor Weather was likely not offering t-shirts to people who have long earned it, thereby confusing them. An unreliable notification system is worse than not having a system at all. Relay operators shouldn't rely on Tor Weather to notify them when their relay fails. They should rather set up their own system instead.
We have tried to find a new maintainer for Tor Weather for years, but without success. We started rewriting Tor Weather using Onionoo as data back-end in 2014, and even though that project didn't produce working code, somebody could pick up this efforts and finish the rewrite. The Roster developers said that they're planning to include an email notification function in Roster. And we developed a simple Python script that provides information about a relay operator's eligibility for acquiring a t-shirt. None of these alternatives is a full replacement of Weather, though.
We encourage the community of Tor relay operators to step up to start their own notification systems and to share designs and code. Tor Weather is still a good idea, it just needs somebody to implement it.
Tor Weather is discontinued in two steps. For now, new subscriptions are disabled, new welcome messages are not sent out anymore, and existing subscriptions continue working until June 30, 2016. From July 1, 2016 on, Tor Weather will not be sending out any emails.
Sorry for any inconvenience caused by this.