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Last Frost usually January 31 or before First
Frost usually November 30-December 31 |
Columns show Low Temperature Ranges
| USDA | Fahrenheit | Celsius | USDA | Fahrenheit | Celsius | Sunset Magazine Zone 13 is considered the low desert region of the southwest, it includes Phoenix, Yuma, Palm Springs, Death Valley and a narrow strip running the length of the lower Colorado. The winters are nearly non-existent, with only 15 nights of freezing temperatures ranging from 13°F to 19°F and an average minimum of 37°F. Summers are hot with average highs of 106°F to 108°F. Rainfall varies upon location with virtually none in the Mojave and 14 plus inches in the Sonoran desert. |
| 1 | Below -50 | Below -45.6 | 6b | -5 0 | -17.8 -20.5 | |
| 2a | -50 -45 | -42.8 -45.5 | 7a | 0 5 | -15.0 -17.7 | |
| 2b | -45 -40 | -40.0 -42.7 | 7b | 5 10 | -12.3 -14.9 | |
| 3a | -40 -35 | -37.3 -39.9 | 8a | 10 15 | -9.5 -12.2 | |
| 3b | -35 -30 | -34.5 -37.2 | 8b | 15 20 | -6.7 -9.4 | |
| 4a | -30 -25 | -31.7 -34.4 | 9a | 20 25 | -3.9 -6.6 | |
| 4b | -25 -20 | -28.9 -31.6 | 9b | 25 30 | -1.2 -3.8 | |
| 5a | -20 -15 | -26.2 -28.8 | 10a | 30 35 | 1.6 -1.1 | |
| 5b | -15 -10 | -23.4 -26.1 | 10b | 35 40 | 4.4 1.7 | |
| 6a | -10 -5 | -20.6 -23.3 | 11 | above 40 | above 4.5 |
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Mountain States Wholesale Nursery webmaster george@mswn.com January 05, 2009 |