'altered weather' is correct and usable in written English.
You could use it to describe when the weather changes or has been affected somehow. For example: "After a long dry spell, altered weather finally returned to the area."
In the meantime, these slight changes in temperature have altered weather patterns for many ecosystems and will continue to do so.
It is clear from my personal and professional experience that environmental change, including climate change, is among the most significant of these: rising temperatures, altered weather patterns, urbanisation and habitat loss have serious implications for nutrition, disasters and diseases such as dengue, malaria and ebola.
The dates for this divergence window span the Eocene Oligocene extinction event, during which time climate cooling took place and changes in ocean currents altered weather patterns.
Altered weather patterns trigger environmental catastrophes.
Altered weather patterns and changes in precipitation and temperature resulting from climate change are likely to affect the distribution and incidence of food and water-borne diseases in Malaysia.
"Climate change, altered weather cycles and transformations in the environment are also having a big negative impact.
Climate change sharpens every threat by altering weather patterns, extending droughts, strengthening storms.
They also wonder if the bacteria could migrate into the upper atmosphere and alter weather patterns.
Already, the reduction in sea ice is altering weather patterns in the Arctic region, and perhaps beyond.
As the global average temperature rises, it alters weather systems, changing patterns of heat and cold and shifting wind currents.
For the first time since 1998, the Pacific is shifting into a warm phase, El Niño, that can alter weather patterns from Asia to the Americas, federal climatologists said.
