Uranus stations Rx in Aries on July 26th (at 20 degrees). This will intensify its agenda of subjective rebellion; breaking the rules because it's the best thing for whoever is breaking the rules. Aries can be selfish, because that's what survival is about for this sign.
Anytime a planet stations Rx, its energy is internalized and intensified. It revisits, or hammers the point home. This Uranus Rx transit will be no different. If you've been avoiding change, events will conspire to make that change unavoidable. It will feel intolerable to maintain an outdated situation. Or someone else will foist that change on you, because it's part of their agenda.
Uranus' Rx station will coincide with its square to Mars (ruler of Aries) in Cancer. The square will be exact on July 25th (when Uranus is direct) but will extend to July 26th, even though the square will no longer be exact. Mars in Cancer is actions expressed via subjective needs. Square Uranus, you get a disruption of those needs, or a sudden urge to do something because it feels right. Uranus's Rx station will intensify this. The Mars/Uranus square will coincide with Venus' Rx station in Virgo, suggesting that sudden actions will be related to what Venus is examining more closely. Venus in Virgo can also signify efforts to correct something that's been broken (Mars square Uranus can signify ruptures or accidents).
But Mars will be trining Chiron Rx (at 21 deg Pisces) from July 25th to 26th. Maybe you'll be agitating on behalf of someone who can't fight for themselves. Or, your sudden impulse could be exactly what's needed in order to lance the festering, emotional wound. Whether you're acting for yourself or someone else, there will be a high degree of subjective reasoning.
Uranus' Rx transit will cover 20 to 16 degrees Aries (where it will station direct on December 25th, 2015). This degree range will be the hot zone for the Cardinal signs.