USDA Hardiness Zone 9a
Frost Dates for 96002 — Redding, California
NOAA 1991–2020 normals from Redding Municipal Airport, CA (497 ft), 2 miles southeast.
Updated
In Redding, the last spring frost (32°F) is around March 3 in half of years and has passed by April 9 in nine years out of ten. The first fall frost comes around November 21, as early as November 7 one year in ten, leaving a typical freeze-free season of 261 days (NOAA, Redding Municipal Airport, CA).
- Last spring frost
- March 3
- First fall frost
- November 21
- Growing season
- 261 days
- Hardiness zone
- 9a
50% probability
50% probability
freeze-free, 50%
20 to 25°F (-6.7 to -3.9°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 18%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
5 of 28 observed
NOAA normal
Frost risk by date in Redding
Half of springs at Redding Municipal Airport, CA see their last 32°F night by March 3; only one in ten is past it by January 31, and one in ten still has one after April 9. Planting tender crops after March 17 leaves a 30% risk of a frost on them, after March 31 20%, and after April 9 10%. The 37 days between the even-odds date and the one-in-ten date is wider than at 79% of the 220 California stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.
In fall the first 32°F night comes by November 21 in half of years, as early as November 7 one year in ten, and holds off past December 7 one year in ten. A hard freeze of 28°F follows 16 days later, around December 7; in spring the one-in-ten date for 28°F is March 1, 39 days before the 32°F one. The freeze-free season lasts 261 days in a typical year, shorter than at 63% of the 219 California stations; it reaches 299 days one year in ten and falls short of 223 one year in ten. On average 27 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 35 days longer, to about April 7, and return around November 9. Nights of 24°F, cold enough to damage hardier plants, come in 52% of winters and 16°F in 2%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Mar 9 | Mar 20 | Mar 29 | Apr 3 | Apr 7 | Apr 12 | Apr 16 | Apr 21 | Apr 26 |
| 32°F | Jan 31 | Feb 13 | Feb 21 | Feb 27 | Mar 3 | Mar 9 | Mar 17 | Mar 31 | Apr 9 |
| 28°F95% of yrs | Dec 20 | Dec 31 | Jan 8 | Jan 19 | Jan 27 | Feb 2 | Feb 12 | Feb 20 | Mar 1 |
| 24°F52% of yrs | Dec 5 | Dec 15 | Dec 22 | Dec 27 | Jan 1 | Jan 6 | Jan 13 | Jan 22 | Feb 2 |
| 20°F13% of yrs | too rare for a date | ||||||||
| 16°F2% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 28 | Nov 1 | Nov 4 | Nov 6 | Nov 9 | Nov 12 | Nov 14 | Nov 18 | Nov 22 |
| 32°F | Nov 7 | Nov 11 | Nov 16 | Nov 19 | Nov 21 | Nov 24 | Nov 28 | Dec 1 | Dec 7 |
| 28°F95% of yrs | Nov 20 | Nov 26 | Dec 1 | Dec 4 | Dec 7 | Dec 12 | Dec 16 | Dec 24 | Jan 5 |
| 24°F52% of yrs | Nov 30 | Dec 3 | Dec 9 | Dec 14 | Dec 18 | Dec 25 | Jan 1 | Jan 7 | Jan 22 |
| 20°F13% of yrs | too rare for a date | ||||||||
| 16°F2% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Redding Municipal Airport, CA, 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 96002 →Compare Redding with another place →
Weather by month in Redding
July is the warmest month at Redding Municipal Airport, CA, averaging 100°F by day and 67°F at night; December is the coldest at 56°F and 37°F. A freezing night is all but certain in December (a 90% chance or more). From May to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 77% of years and March still brings one in 45% of years and April still brings one in 20% of years.
Warmth for growing adds up to 5,311 growing degree days a year (base 50°F), more than at 74% of the 283 California stations. 37% of them (1,940) have built up by the end of June, and July adds the most, 1,037. Precipitation totals 33.5 inches a year, most in December (6.3") and least in July (0.1"); May to September bring 10% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 57 | 38 | 6.0 | 88% | 8 | 35 |
| Feb | 61 | 40 | 5.5 | 77% | 4 | 75 |
| Mar | 66 | 43 | 4.6 | 45% | 2 | 165 |
| Apr | 72 | 47 | 2.4 | 20% | <1 | 288 |
| May | 82 | 54 | 1.8 | 0% | 0 | 563 |
| Jun | 92 | 62 | 0.8 | 0% | 0 | 815 |
| Jul | 100 | 67 | 0.1 | 0% | 0 | 1037 |
| Aug | 98 | 64 | 0.1 | 0% | 0 | 961 |
| Sep | 92 | 58 | 0.5 | 0% | 0 | 758 |
| Oct | 79 | 50 | 1.9 | 3% | 0 | 460 |
| Nov | 64 | 42 | 3.5 | 75% | 3 | 129 |
| Dec | 56 | 37 | 6.3 | 95% | 10 | 27 |
Monthly normals 1991–2020 at Redding Municipal Airport, CA (497 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, Whiskeytown Rsvr, CA, 11 miles northwest of Redding and 798 feet higher, has a last frost 18 days earlier (February 13), a first frost 22 days later (December 13), a season 43 days longer.
When it snows in Redding, California
Measurable snow is rare here: only 5 of 28 winters from 1991 to 2020 recorded 0.1 inch or more at Whiskeytown Rsvr, CA, 11.4 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 96002
| When | What to do |
|---|---|
| December 23 – January 6 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| January 6 – January 20 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| February 3 – February 17 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| March 3 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 29 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by November 7 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 21 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 96002 is 2 miles from Redding Municipal Airport, CA, which stands at 497 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 96002 in zone 9a, the band where the coldest night of the year averaged 20 to 25°F (-6.7 to -3.9°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across California →
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.