Frost Dates: First and last frost dates for Heber Black Mesa Rs, AZ

ℹ️ How to read these charts for the spring

As spring unfolds, the risk of frost gradually decreases each day until your tender plants are finally safe. The probabilities shown in the chart help you make smart decisions about when to plant.

While frost typically forms at 32°F, tender plants can be damaged even when temperatures are slightly higher. Air temperatures are often measured several feet above the ground, but temperatures at plant level can be several degrees colder. Protected areas like porches help by blocking radiational cooling. Given these variables, we consider 36°F the "caution zone" for frost-sensitive plants.

Key dates for your spring planting:

  • By June 28, you have a 90% chance of being frost-free — this is your "safe date" for planting tender crops
  • Around June 11, there's a 50/50 chance of frost — check weather forecasts carefully if planting now
  • Before May 31, there's still an 80% risk of frost — too early for tomatoes and other tender plants unless you're prepared to protect them

If the 10-day forecast shows no temperatures below 40°F, you might safely plant earlier than the above dates suggest. Many gardeners watch for this weather window to get a head start on the growing season.

In the Spring
Temperature 10% 20% 30% 40% 50% 60% 70% 80% 90%
Last 16° Apr 5 Mar 26 Mar 18 Mar 12 Mar 6 Feb 27 Feb 21 Feb 13 Feb 3
Last 20° May 4 Apr 23 Apr 14 Apr 7 Apr 1 Mar 25 Mar 18 Mar 10 Feb 26
Last 24° May 19 May 11 May 5 Apr 30 Apr 25 Apr 21 Apr 16 Apr 10 Apr 2
Last 28° Jun 3 May 26 May 21 May 17 May 13 May 8 May 4 Apr 29 Apr 22
Last 32° Jun 13 Jun 7 Jun 3 May 30 May 27 May 23 May 20 May 16 May 10
Last 36° Jun 28 Jun 22 Jun 18 Jun 14 Jun 11 Jun 7 Jun 4 May 31 May 25

ℹ️ How to read these charts for the fall

As summer ends in Heber Black Mesa Rs, AZ, nighttime temperatures begin to drop, and your risk of frost increases with each passing day. Knowing when to expect frost helps you harvest sensitive crops and extend your growing season with protection methods.

The chart below shows the probability of experiencing specific temperatures on various dates. Here's what this means for your garden:

1
Early warning: Around September 29, there's a 20% chance of 32°F — start monitoring forecasts and have plant covers ready
2
Decision time: By October 11, there's a 50% chance of frost — harvest tomatoes, peppers, and other tender crops or prepare protection
3
Last chance: By October 23, there's an 80% chance of seeing 32°F — most tender plants will be damaged without protection
4
Another perspective: You have only a 1 in 5 chance of making it past October 23 without a freezing night

These probabilities help you time your end-of-season harvests and know when to apply protective measures like row covers, cloches, or cold frames to extend your harvest.

In the Fall
Temperature 10% 20% 30% 40% 50% 60% 70% 80% 90%
First 16° Nov 6 Nov 12 Nov 17 Nov 20 Nov 24 Nov 27 Dec 1 Dec 5 Dec 12
First 20° Oct 27 Nov 1 Nov 4 Nov 7 Nov 10 Nov 13 Nov 17 Nov 20 Nov 25
First 24° Oct 16 Oct 22 Oct 27 Oct 30 Nov 3 Nov 6 Nov 10 Nov 14 Nov 20
First 28° Oct 4 Oct 9 Oct 13 Oct 17 Oct 20 Oct 23 Oct 26 Oct 30 Nov 5
First 32° Sep 23 Sep 29 Oct 4 Oct 8 Oct 11 Oct 15 Oct 19 Oct 23 Oct 30
First 36° Sep 8 Sep 14 Sep 18 Sep 22 Sep 26 Sep 29 Oct 3 Oct 7 Oct 13

📍 Frost Dates for other nearby locations

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Data is provided by the NOAA National Centers for Environmental Information.