Monthly plague cases, precipitation, temperature, and crop harvests in West Nile region of Uganda. (A) Number of monthly suspected human plague cases in Arua and Zombo districts from 1999 to 2011. Averaged monthly (B) precipitation (mm) and (C) mean temperatures (°C) at field sites above and below 1300 m. Climate variables are long-term averages for 1999–2008 derived from Weather Research and Forecasting model simulations described in Monaghan et al. . (D) Percentage of homesteads above 1300 m that report harvesting millet/maize, potatoes, pumpkins, beans, and ground nuts in each month.