USDA Hardiness Zone 8a
Frost Dates for 76950 — Sonora, Texas
NOAA 1991–2020 normals from Sonora, TX (2,138 ft), 10 miles northwest.
Updated
In Sonora, the last spring frost (32°F) is around April 1 in half of years and has passed by April 20 in nine years out of ten. The first fall frost comes around November 6, as early as October 24 one year in ten, leaving a typical freeze-free season of 221 days (NOAA, Sonora, TX).
- Last spring frost
- April 1
- First fall frost
- November 6
- Growing season
- 221 days
- Hardiness zone
- 8a
50% probability
50% probability
freeze-free, 50%
10 to 15°F (-12.2 to -9.4°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 22%
- Snow per year
- 0.2"
median, 1991–2020
median, 1991–2020
4 of 18 observed
NOAA normal
Frost risk by date in Sonora
Half of springs at Sonora, TX see their last 32°F night by April 1; only one in ten is past it by March 8, and one in ten still has one after April 20. Planting tender crops after April 8 leaves a 30% risk of a frost on them, after April 13 20%, and after April 20 10%. The 19 days between the even-odds date and the one-in-ten date is narrower than at 63% of the 339 Texas stations behind this site's ZIP pages.
In fall the first 32°F night comes by November 6 in half of years, as early as October 24 one year in ten, and holds off past November 24 one year in ten. A hard freeze of 28°F follows 10 days later, around November 16; in spring the one-in-ten date for 28°F is April 7, 13 days before the 32°F one. The freeze-free season lasts 221 days in a typical year, shorter than at 86% of the 339 Texas stations; it reaches 249 days one year in ten and falls short of 197 one year in ten. On average 70 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 12 days longer, to about April 13, and return around October 28. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 76%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Mar 26 | Apr 2 | Apr 6 | Apr 10 | Apr 13 | Apr 16 | Apr 19 | Apr 24 | Apr 29 |
| 32°F | Mar 8 | Mar 15 | Mar 21 | Mar 26 | Apr 1 | Apr 4 | Apr 8 | Apr 13 | Apr 20 |
| 28°F | Feb 22 | Feb 28 | Mar 5 | Mar 9 | Mar 13 | Mar 19 | Mar 25 | Mar 31 | Apr 7 |
| 24°F | Feb 7 | Feb 15 | Feb 21 | Feb 25 | Mar 1 | Mar 4 | Mar 8 | Mar 13 | Mar 23 |
| 20°F98% of yrs | Jan 7 | Jan 22 | Jan 31 | Feb 6 | Feb 11 | Feb 18 | Feb 23 | Feb 28 | Mar 7 |
| 16°F76% of yrs | Dec 16 | Jan 1 | Jan 8 | Jan 18 | Jan 27 | Feb 1 | Feb 7 | Feb 16 | Mar 1 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 12 | Oct 18 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 3 | Nov 6 | Nov 13 |
| 32°F | Oct 24 | Oct 28 | Nov 1 | Nov 3 | Nov 6 | Nov 8 | Nov 13 | Nov 17 | Nov 24 |
| 28°F | Oct 31 | Nov 4 | Nov 8 | Nov 12 | Nov 16 | Nov 19 | Nov 24 | Dec 1 | Dec 5 |
| 24°F | Nov 8 | Nov 15 | Nov 20 | Nov 25 | Nov 29 | Dec 2 | Dec 6 | Dec 12 | Dec 19 |
| 20°F98% of yrs | Nov 20 | Nov 27 | Dec 2 | Dec 6 | Dec 11 | Dec 18 | Dec 24 | Jan 1 | Jan 13 |
| 16°F76% of yrs | Dec 2 | Dec 7 | Dec 13 | Dec 21 | Dec 28 | Jan 1 | Jan 9 | Jan 19 | Feb 5 |
Freeze probabilities 1991–2020 at Sonora, TX, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 76950 →Compare Sonora with another place →
Weather by month in Sonora
July is the warmest month at Sonora, TX, averaging 96°F by day and 72°F at night; January is the coldest at 61°F and 31°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 51% of years.
Warmth for growing adds up to 6,271 growing degree days a year (base 50°F), fewer than at 55% of the 351 Texas stations. 42% of them (2,623) have built up by the end of June, and July adds the most, 1,040. Precipitation totals 22.7 inches a year, most in September (3.2") and least in December (0.7"); May to September bring 58% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 61 | 31 | 1.0 | 100% | 21 | 48 |
| Feb | 66 | 35 | 1.2 | 100% | 13 | 100 |
| Mar | 73 | 43 | 1.6 | 94% | 7 | 281 |
| Apr | 81 | 51 | 1.7 | 51% | 2 | 483 |
| May | 88 | 62 | 2.4 | 1% | 0 | 767 |
| Jun | 94 | 69 | 2.6 | 0% | 0 | 943 |
| Jul | 96 | 72 | 2.3 | 0% | 0 | 1040 |
| Aug | 96 | 71 | 2.6 | 0% | 0 | 1029 |
| Sep | 89 | 64 | 3.2 | 0% | 0 | 792 |
| Oct | 81 | 52 | 2.2 | 29% | 1 | 516 |
| Nov | 70 | 41 | 1.2 | 94% | 8 | 205 |
| Dec | 62 | 32 | 0.7 | 100% | 18 | 67 |
Monthly normals 1991–2020 at Sonora, TX (2,138 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Eldorado, TX, 29 miles north of Sonora and 302 feet higher, has a last frost 10 days earlier (March 22), a first frost 4 days later (November 10), a season 13 days longer.
When it snows in Sonora, Texas
Measurable snow is rare here: only 4 of 18 winters from 1991 to 2020 recorded 0.1 inch or more at Rocksprings, TX, 36.6 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 76950
| When | What to do |
|---|---|
| January 21 – February 4 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 4 – February 18 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 4 – March 18 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 1 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 14 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 23 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 6 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 76950 is 10 miles from Sonora, TX, which stands at 2,138 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 76950 in zone 8a, the band where the coldest night of the year averaged 10 to 15°F (-12.2 to -9.4°C) over 1991–2020; a zone describes winter lows, not frost dates.
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.