This research develops several indicators for assessing local vulnerability to climate change in the agricultural sector of Tocantins, Brazil, where the Inter-American Development Bank is carrying irrigation investments via the Development Program for the Southwest (PRODOESTE). Vulnerability to climate indicators are constructed from exposure and sensitivity indicators and estimated using panel data on yields and farmers’ profits as a function of climatic variables. Our baseline assessment indicates that those municipalities where PRODOESTE operates present medium to high levels of precipitation and temperature vulnerability, relative to the rest of Tocantins. In particular, temperature vulnerability is higher than precipitation vulnerability. We also find that vulnerability will increase in all municipalities due to climate change and it will be higher in the long-run and in more extreme climate change scenarios. Finally, irrigation is evaluated as a potential adaptation strategy and it is found to reduce climate vulnerability in the long-term, indicating that PRODOESTE’s irrigation investments may be successful at reducing vulnerability due to climate change.