Frost Dates: First and last frost dates for Union City, TN

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 April 30, you have a 90% chance of being frost-free — this is your "safe date" for planting tender crops
  • Around April 16, there's a 50/50 chance of frost — check weather forecasts carefully if planting now
  • Before April 8, 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° Mar 5 Feb 26 Feb 20 Feb 15 Feb 10 Feb 6 Feb 1 Jan 26 Jan 16
Last 20° Mar 13 Mar 6 Mar 1 Feb 24 Feb 20 Feb 15 Feb 11 Feb 5 Jan 29
Last 24° Mar 22 Mar 16 Mar 12 Mar 9 Mar 5 Mar 2 Feb 27 Feb 23 Feb 17
Last 28° Apr 10 Apr 5 Apr 1 Mar 29 Mar 26 Mar 23 Mar 20 Mar 16 Mar 11
Last 32° Apr 18 Apr 13 Apr 10 Apr 7 Apr 5 Apr 2 Mar 30 Mar 27 Mar 23
Last 36° Apr 30 Apr 25 Apr 22 Apr 19 Apr 16 Apr 14 Apr 11 Apr 8 Apr 3

ℹ️ How to read these charts for the fall

As summer ends in Union City, TN, 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 October 12, there's a 20% chance of 32°F — start monitoring forecasts and have plant covers ready
2
Decision time: By October 23, there's a 50% chance of frost — harvest tomatoes, peppers, and other tender crops or prepare protection
3
Last chance: By November 3, 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 November 3 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 21 Dec 1 Dec 9 Dec 16 Dec 22 Dec 29 Jan 5 Jan 13 Jan 26
First 20° Nov 16 Nov 23 Nov 28 Dec 2 Dec 6 Dec 10 Dec 15 Dec 20 Dec 27
First 24° Nov 6 Nov 12 Nov 16 Nov 19 Nov 22 Nov 26 Nov 29 Dec 3 Dec 9
First 28° Oct 23 Oct 28 Nov 1 Nov 4 Nov 7 Nov 10 Nov 13 Nov 17 Nov 23
First 32° Oct 7 Oct 12 Oct 16 Oct 20 Oct 23 Oct 26 Oct 30 Nov 3 Nov 8
First 36° Sep 30 Oct 4 Oct 7 Oct 10 Oct 12 Oct 14 Oct 17 Oct 19 Oct 23

📍 Frost Dates for other nearby locations

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