Climate change is affecting the frost-free season in these cities, which also affects the allergy season.
Longer frost-free seasons mean longer allergy seasons, a trend impacting all regions of the country.
Following a year of weather extremes, disasters and policy clashes, we asked our readers to help us pick out the most important climate stories from the U.S. in 2017.
As climate change stokes polluting fires, southern California's most vulnerable are being hit the hardest.
Warming temperatures combined with drought conditions are major factors for the increase in wildfires.
Smoke pollution is leading to serious public health impacts as large wildfires across the American West become more frequent and destructive.
As climate change fuels large wildfires, the pollution they're releasing is making Americans sick and undermining decades of progress in cleaning the air.