1. Yavapai County Climate Jeff Schalau Agent, Agriculture & Natural Resources University of Arizona Cooperative Extension Yavapai County

2. Arizona’s Climate Bimodal Precipitation Pattern Bimodal Precipitation Pattern Wide Diurnal Temperature Fluctuations Wide Diurnal Temperature Fluctuations Elevation Differences Cause Variability Elevation Differences Cause Variability Highly Variable Summer Precipitation Highly Variable Summer Precipitation Periodic Drought Periodic Drought Monsoon Most Dependable in Southeastern Portion of the State Monsoon Most Dependable in Southeastern Portion of the State

4. Freeze Probabilities - Prescott Earliest90%80%70%60%50%40%30%20%10%Latest 4/144/265/35/85/135/185/215/265/316/26/17 Spring Freeze Probabilities (32.5 degrees F) Earliest10%20%30%40%50%60%70%80%90%Latest 8/239/209/2510/110/510/1110/1410/1610/2110/2711/5 Fall Freeze Probabilities (32.5 degrees F) Average Growing Season = 140 days

6. Freeze Probabilities - Cottonwood Earliest90%80%70%60%50%40%30%20%10%Latest 3/113/243/264/34/94/154/204/254/295/55/8 Spring Freeze Probabilities (32.5 degrees F) Earliest10%20%30%40%50%60%70%80%90%Latest 10/1810/2410/2510/2911/411/711/1011/1211/1411/1811/25 Fall Freeze Probabilities (32.5 degrees F) Average Growing Season = 194 days

9. El Nino and La Nina Related to temperature and current in the equatorial Pacific Ocean Related to temperature and current in the equatorial Pacific Ocean El Nino increases the probability of winter precipitation El Nino increases the probability of winter precipitation La Nina almost always forecasts low winter precipitation La Nina almost always forecasts low winter precipitation

11. Arizona’s Paleoclimate Data gathered from tree ring and pack rat midden studies Data gathered from tree ring and pack rat midden studies