Surprise, AZ 85374 Frost Dates
Surprise, AZ: when does the frost end?
Typically, the last spring freeze lands around 01/20, roughly 145 days out. Fall's first freeze usually shows up around 12/15, roughly 331 days after the last spring frost.
Surprise sits in USDA Zone 9b (25 to 30°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
With roughly 16 weeks until Surprise's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Surprise's last frost
01/20 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/18 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/23 and only about 1 year in 10 sees frost after that.
Surprise against the rest of the dataset
About 331 days separate Surprise's last and first frost, putting it 2,924 of 40,283 ZIP codes nationally. Within AZ, it ranks 171 of 506.
Learn more
Before leaning on 85374's figures: local microclimates explains what one yard in Surprise can differ from the 85374 normal, while zone vs. frost date explains why Zone 9b and Surprise's frost date answer different questions.