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

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

4. Freeze Probabilities - Prescott
Spring Freeze Probabilities (32.5 degrees F)
Earliest
90%
80%
70%
60%
50%
40%
30%
20%
10%
Latest
4/14
4/26
5/3
5/8
5/13
5/18
5/21
5/26
5/31
6/2
6/17
Fall Freeze Probabilities (32.5 degrees F)
Earliest
10%
20%
30%
40%
50%
60%
70%
80%
90%
Latest
8/23
9/20
9/25
10/1
10/5
10/11
10/14
10/16
10/21
10/27
11/5
Average Growing Season = 140 days

6. Freeze Probabilities - Cottonwood
Spring Freeze Probabilities (32.5 degrees F)
Earliest
90%
80%
70%
60%
50%
40%
30%
20%
10%
Latest
3/11
3/24
3/26
4/3
4/9
4/15
4/20
4/25
4/29
5/5
5/8
Fall Freeze Probabilities (32.5 degrees F)
Earliest
10%
20%
30%
40%
50%
60%
70%
80%
90%
Latest
10/18
10/24
10/25
10/29
11/4
11/7
11/10
11/12
11/14
11/18
11/25
Average Growing Season = 194 days

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